Wellbore servicing fluids comprising cationic polymers and methods of using same.

(54) Title: WATER SERVICE FLUIDS THAT INCLUDE CATIONIC POLYMERS AND METHODS OF USE THEREOF.

(54) Title: WELLBORE SERVICING FLUIDS COMPRISING CATIONIC POLYMERS AND METHODS OF USING SAME.

(57) Summary

A method comprising placing a well service fluid with a cationic polymer in wells where the cationic polymer has a molecular weight of from about 300,000 Daltons to about 10,000,000 Daltons. A composition with a well service fluid, a cationic polymer and a brine.

(57) Abstract

A method comprising placing a wellbore servicing fluid comprising a cationic polymer into wellbore where the cationic polymer has a molecular weight of from about 300,000 Daltons to about 10,000,000 Daltons. A composition comprising a wellbore servicing fluid, a cationic polymer, and a brine.

<img file="MX344584B_D0001.tif" />

PATENT TITLE NO. 344584 ___SE___ ssaíTMU mk® »·

Mexican Institute of Industrial Property

<img file="MX344584B_D0002.tif" />

<td>Headlines):</td><td>CHEVRON PHILIPS CHEMICAL COMPANY LP</td>

<td>Home:</td><td>10001 Six Pines Drive, The Woodlands, Texas, 77380, USA</td>

<td>Denomination:</td><td>WELL SERVICE FLUIDS INCLUDING CATIONIC POLYMERS AND METHODS FOR USING THEM.</td>

<td>Classification:</td><td>lnt.CI.8: C09K8 / 12; C09K8 / 40; C09K8 / 68; C09K8 / 72</td>

Inventor (s): KELLY B FOX

REQUEST

Number:

International filing date:

MX / a / 2011/007954 February 2010

PRIORITY

Country:

Date:

Number:

US

Validity: Twenty years of February 2009

12/371,895

Expiration Date: February 11, 2030

The reference patent is granted based on articles 1 ', 2nd section V, 6^or section III, and 59 of the Industrial Property Law.

- In accordance with article 23 of the Industrial Property Law, this patent has an agency for twenty years, which cannot be extended, counted from the date of filing of the international application and will be subject to the payment of the same to keep it in force. rights. ; ·&gt;

The subscriber of the present title does so based on the provisions of the 'a- (cutos β® fícoones III and 7 ° bis 2 of the Industrial Property Law (tSario Ofiaísi de la FederacIfeXD OF) 06/27/1981, re-circulated on 02/08/1994,26 / 10/1996, 12/26/1987, 05/17/1999, '* 01/26/2004, 06/16/200 $, 01/25 / 2Λ6, 06/05 / 2009.06 / O ^^ Q, 06/18/2010, 06/28.'20'0. 01/27/2012 and 09/34/2012); articles ^⁰, 3rd fraction V. Item a), 4^or and 12th fractions I and III of the Regulation of 'l-.s'-lu'c Mexca-o de -a Pmpiedad Ind · nal (DOF 14/12/19 $, amended on, 01/07/2002, 15 / 07/200 $ 28/07 / 2¾¼ and 7/7/2007); items' V 4 '5' pull V subsection 4) *^p Fractions I and III and 30 of the Organic Statute of the Mexican Institute of Industrial Property (DOF 27/12/1999, refofWed &amp; * el19 / 10/2002, 29/07/2004, 04/08/2004 and 10 ^ 09/2007 ); 1st, 3rd

Industrial. (DOF 12/15/1999, amended on 02/04/2000, 07/29/2004, 08/04/2004 and 09/13/2007).

Issue Date: December 20, 2016

THE DIVISIONAL DIRECTOR OF PATENTS

<img file="MX344584B_D0003.tif" />

NAHANNY CANAL REYES

Sand! No. 550. Floor 1.

Coi. Pueblo Santa María Tepepan, Xochimilco. CP 16020,

Mexico City

Tei. (55) 53 34 07 00 www.impi.ciob.mx

<img file="MX344584B_D0004.tif" />

<img file="MX344584B_D0005.tif" />

WELL SERVICE FLUIDS I COMPrJ ^ MÍ iBlí

-------------------------------------------------- ----------- nBTffWb Muti¿AÑ &lt;.

«THE PtORWAF

CHARACTERISTICS AND METHODS OF USE OF THE SAME '”™ *'

<img file="MX344584B_D0006.tif" />

<img file="MX344584B_D0007.tif" />

FIELD OF THE INVENTION

This description generally refers to well service fluids. More specifically, this description relates to well service fluids comprising cationic polymers and methods of preparing and using them.

BACKGROUND OF THE INVENTION

Underground deposits of natural resources such as gas, water, and crude oil are commonly recovered by drilling wells into residual underground formations or areas containing such deposits. Various well service fluids are employed in the drilling and preparation of adjacent wells and underground formations for material recovery therefrom. For example, a drilling fluid is normally circulated through the well as it is drilled. Generally, drilling fluid can be used to cool and lubricate the bit, remove drill cuttings, condition the hole, control well pressures. Once a productive zone is found, the drilling fluid will commonly be replaced by a drilling fluid, which has a role similar to that of an ordinary drilling mud.^T^ £ &amp; "m $ te

<img file="MX344584B_D0008.tif" />

consist of a brine to minimize damage to production rock. Completion fluids can be used during the well completion steps, and completion fluids can be used to perform repair work on the well.

Fluids suitable for use in a well generally have sufficient density to overcome the reservoir pressure and prevent unwanted fluid from entering the well. Pickles are used for these purposes because their density can be easily controlled by adjusting their compositions. Furthermore, these liquids may contain suspended solids in order to control the loss of fluids in the rock adjacent to the well.

A challenge to using brines in well service is the generally low viscosity of fluids. Higher viscosity brine-containing liquids will generally be useful for several reasons. For example, these fluids may find utility in controlling fluid losses as the rate at which the fluid can enter the porous matrix of the rock reservoir as the filtrate, during fluid loss, is proportional to the viscosity of the fluid. Furthermore, these fluids may find additional utility if they are capable of transporting solids of

IMPI, r-. ,,,. ,_n INSTITUTO MEXICANO drilling, solids trapped in the p ptg d ^^ ág ^ gr solids that would also depend on the viscosity of the _;fluid. Polymers comprising hydroxyethyl cellulose (HEC) or xanthan gum have been used for thickening of well service fluids as they dissolve in brines and to produce shear thinning viscosity, as well as to provide solid suspension capacity and fluid loss control . However, these polymers (i.e.HEC, xanthan gum) lose their thickening ability at relatively low temperatures, limiting their usefulness at temperatures above around 240 ° F (115.6 ° C) for

HEC, and 280 ° F (137.8 ° C) for xanthan gum. Furthermore, these polymers can interlock with multivalent cations in brine at elevated temperatures, forming gels or precipitates. Loss of solubility of a thickener (eg HEC, xanthan gum) in the brine can cause formation or damage to the sand pack, thereby restricting the flow of hydrocarbons from the well. Therefore a need exists for improved well service fluids comprising brines and methods of using them.

BRIEF DESCRIPTION OF THE INVENTION

Here we describe a method that involves placing a well service fluid with a cationic polymer in wells where the cationic polymer has a weight

IMPI

Molecular MEXICAN INSTITUTE of approximately 300,000 Daltons

<img file="MX344584B_D0009.tif" />

to approximately 10,000,000 Daltons (10.0QfL- ririn g / mni i

Also described herein is a composition with a well service fluid, a cationic polymer and a brine.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of this description, reference is now made to the following brief description, together with the accompanying drawings and detailed description, where similar reference numbers represent similar parts.

Figure 1 is an illustration of a phase separation experiment.

Figure 2 is a graph of viscosity as a function of cutting speed of the samples from Example 1.

Figure 3 is a graph of shear stress as a function of shear rate of the samples from Example 1.

Figure 4 is a graph of viscosity as a function of the temperature of the samples from Example 3.

Figure 5 is a graph of viscosity as a function of the cutting speed of the samples in Example 5.

Figure 6 is a graph of the degree of phase separation as a function of time for the samples in Example 5.

Figure 7 is a graph of fluid loss versus square root of time for samples of the

IMPIOUS

MUIONl INSTITUTE · I heard INDUSTRIAL PROPERTY example 6.

Figure 8 is a graph of viscosity as a function of the cutting speed of the samples in Example 7.

<td></td><td>Figure</td><td>9 is</td><td>a graph</td><td>viscosity like</td><td>a</td><td>function</td>

<td>of the 7</td><td>weather</td><td>at 350 °</td><td>F (176.7 ° C)</td><td>for samples</td><td>of the</td><td>example</td>

<td> / ·</td><td>Figure</td><td>10 is</td><td>a graph</td><td>viscosity like</td><td>a</td><td>function</td>

of the cutting speed of the samples of example 9.

DETAILED DESCRIPTION OF THE INVENTION

It should be understood first that although an illustrative implementation of one or more modalities are provided below, the described systems and / or methods may be applied using any number of techniques, either currently known or in existence. The description should in no way be limited to the illustrative implementations, drawings and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but may be modified within the scope of the appended claims together with their full scope of equivalents .

Described here are well service fluids that encompass a cationic polymer. Well service fluids encompassing a cationic polymer and a brine are also described in this document. In this document a well service fluid that can be placed in and / or

IM refers to NS-uwi¹^

INDUSTRIAL

<img file="MX344584B_D0010.tif" />

an underground formation for the recovery of material from the formation or the well. Thus, the well service fluids can serve as, for example, a drilling fluid, a working fluid, completion fluid, fracture fluid, etc. It should be understood that the underground formation encompasses areas below exposed land and areas below land covered by water, such as sea or ocean water.

Well service fluids comprising a cationic polymer and a brine are hereafter referred to as cationic polymer-brine compositions (CPBC). CPBC can be used in well service such as for example CPBC can be used to control fluid loss and / or suspend solids in a well. Well service methods with a CPBC are described in more detail later in this document.

In one embodiment, the CPBC comprises a cationic polymer (CP). CP herein refers to polymers composed of positively charged and negatively charged components. A suitable CP for use in this description is any CP compatible with the other components of the CPBC. Furthermore, a suitable CP for use in this description is further characterized ροη ^ τ ^ κϊι &amp; ΜΕί &amp; βίϊο

OF INDUSTRIAL PROPERTY

<img file="MX344584B_D0011.tif" />

Low or insignificant with polyvalent cations that usually appear in brines (for example, Ca + 2, Zn + 2). In one embodiment, the CP has enough molecular weight to be able to impart viscosity to the brine. In this modality, the CP has a molecular weight of approximately 300,000

Dalton g / mol) to approximately 10,000,000

Dalton (10,000,000 g / mol), alternatively about

350,000 Dalton (350,000 g / mol) to approximately 1,000,000

Daltons g / mol), alternatively about

400,000

Daltons (400,000 g / mol) approximately

750,000

Daltons (750,000 g / mol), as an alternative of approximately

450,000 Daltons (450,000 g / mol) to approximately 650,000

Daltons (650,000 g / mol), alternatively about

475,000

Daltons (475,000 g / mol) at approximately 550,000

Daltons (550,000 g / mol), alternatively approximately

500,000

Dalton (500,000 g / mol).

In one embodiment, the CP comprises a polyamine, alternatively a poly (allylamine), or a quaternary amine, alternatively a polyalkyl ammonium halide, alternatively a polyalkyl ammonium halide halide, alternatively a poly diallyl dimethyl ammonium chloride or combinations thereof . In another modality, the CP

IMPIOS comprises a poly ammonium halide

INDUSTRIAL polyvinyl pyrrolidone, a poly vinylimidazole, or combinations thereof.

The CP can be a homopolymer, or a copolymer such as a copolymer of vinylamine and allylamine or a copolymer of acrylamide and allylamine. Examples of

Suitable CPs for use in this disclosure include without limitation poly di allyl dimethyl ammonium chloride homopolymers (poly-DADMAC), poly DADMAC-co-allyl amine, poly

DADMAC-co-vinylpyrrolidone, poly DADMAC-co-vinylimidazoi, poly

DADMAC-co-acrylamide, polyvinylamine, polyvinylpyrrolidone, vinylpyrrolidone-co-methacrylamide-co vinylimidazole, or combinations thereof. CPs of the type described in this document may be linear, branched, or entangled polymers. In some modalities, the CP is not interleaved.

In one embodiment, the CP comprises poly-DADMAC which is commercially available from Northaven Chemicals, SNF Inc. and Ciba Corporation. The molecular structure of poly-DADMAC is:

<img file="MX344584B_D0012.tif" />

where n is from about 1,800 to about

62,200, also approximately

3,000*

<img file="MX344584B_D0013.tif" />

OF THE MONEDAD

INDUSTRIAL

I

<img file="MX344584B_D0014.tif" />

35,000, also approximately

3,000 to approximately

30,000, alternatively n is any number sufficient to produce a cationic polymer with a molecular weight in the ranges disclosed earlier in this document.

In some embodiments, the poly-DADMAC is not crosslinked. In some embodiments, poly-DADMAC is a homopolymer. In some embodiments, poly-DADMAC is a copolymer. For example, a poly-DADMAC copolymer can include, but is not limited to poly DADMAC-co-allylamine, poly DADMAC-co-vinylpyrrolidone, poly DADMAC-co-vinylimidazole and poly DADMAC-co-acrylamide.

In the modality, the CP can be present in the CPBC for an amount of about 0.5 pounds of CP per barrel of the brine (lb / BBl) (0.001427 kg / L), to about 15 lb / BBl (0.042795 kg / L) , alternatively from about 3 lb / BBl (0.008559 kg / L) to about 13 lb / BBl (0.037089 kg / L), alternatively from about 7 lb / BBl (0.019971 kg / L) to about 12 lb / BBl (0.034236 kg / L).

In one embodiment, the CPBC comprises a brine.

Non-limiting examples of brines suitable for use in this disclosure include solutions of sodium bromide (NaBr2), calcium bromide (CaBr2), zinc bromide (ZnBr), potassium bromide (KBr), sodium chloride (NaCl), calcium chloride (CaC12), zinc chloride (ZnC12), (KC1) or combinations thereof.

In one embodiment, the brine

<img file="MX344584B_D0015.tif" />

□ f INDUSTRIAL PROPERTY comprises CaC12, alternatively CaBr2, or ZnBr2. Examples of CaBr2 and ZnBr2 brines suitable for use in this disclosure include without limitation WELLBROM 14.2 and WELLBROM 19.2 respectively where 14.2 and 19.2 denote the density of the brine in pounds per gallon (ppg). WELLBROM 14.2 and

WELLBROM 19.2 are commercially available from Albermarle ™

Corporation.

In one embodiment, the brine can have a density of from about 8.4 lb / gal (1.01 kg / L) to about 19.2 lb / gal (2.30 kg / L), as an alternative from about 9 lb / gal (1.07 kg / L) to approximately 16 lb / gal (1.92 kg / L), as an alternative from around 10 lb / gal (1.20 kg / L) to approximately 14.2 lb / gal (1.70 kg / L). The brine may be present in the CPBC in the amount of about 95 vol.% Based on the total volume of CPBC at about 99.8 vol.%, Also from about 95.5 vol.% To about 99 vol.%, Also about 96 vol. .% to about 98 vol.%.

In one embodiment, the CPBC can be prepared by contacting a brine and a CP, both types described in this document. The contact of the brine and the CP can be made by any means

<img file="MX344584B_D0016.tif" />

brine and CP can be mixed or combined using a mixer, a stirrer, a stirrer and the like. Mixing conditions (mixing speed, time period, etc.) can be determined by a person skilled in the art with the help of this disclosure.

In some embodiments, after mixing, the material may be allowed to hydrate for a period of time and at a temperature sufficient to dissolve the CP. Such time periods and temperatures can be selected or adjusted by a person skilled in the art with the benefit of communicating this disclosure.

In some embodiments, CPBC may include additional additives as deemed appropriate by a person skilled in the art to improve fluid properties. These additives vary according to the intended use of the fluid in the well. Examples of such additives include but are not limited to fluid loss or leak loss additive, such as clay, petroleum soluble resins, mica, talc, glass fibers, carbon fibers, starch, and carboxymethyl cellulose. Examples of other additives include but are not limited to pH modifiers, surfactants, emulsifiers, dispersants, corrosion inhibitors, bactericides, defoamers, formative conditioning agents, or combinations thereof. These individually or in combination.

<img file="MX344584B_D0017.tif" />

Methods for introducing these additives and their effective amounts are known to a person skilled in the art with the help of this disclosure.

A suitable CP for use in the present disclosure may be further characterized by a high degree of solubility in a brine. Without wishing to be bound by theory, the CP will easily be taken in available water and dissolved in the brine. A suitable CP for use in this description will show low or negligible reactivity with the cations dissolved in the brine that can react with the CP to form a gel or precipitate.

A CPBC of the type described herein presents the behavior of a non-Newtonian fluid. A non-Newtonian fluid refers here to a fluid whose flow properties are not described by a simple constant viscosity value. Thus, a log-log plot of shear stress versus shear speed of a non-Newtonian shear thinning fluid has a slope of less than one. The cutting speed and cutting effort are calculated from the measured values ​​of rpm and bob displacement. The calculations depend on the geometry of the rheometer. For example, on a Chandler 5550 viscometer, the calculation is done internally. The index of

<img file="MX344584B_D0018.tif" />

<img file="MX344584B_D0019.tif" />

consistency is the intercept of the line, {the PWOF1EDA »nOOSTRlAL flow is the exponent. Physically, the consistency index can be equated with the viscosity of the fluid, while the flow index can be equated with how the viscosity of the fluid will change as the force is applied. Fluid viscosity can be determined using the calculated shear rate and shear stress as defined in equation 1.

// = 47,880^(5/^-0]

Equation 1 where μ is the viscosity in centipoise and K 'is the consistency index in lb / ft2.

In one embodiment, at a cutting speed of about 0.1 sec-1 to about 10 sec-1, alternatively from about 0.5 sec-1 to about 5 sec-1, alternatively from about 1 sec-1 to about 2 sec -1 CPBC can have a viscosity of about 100 centipoise (0.1 Pa-s) to about 40,000 centipoise (40 Pa-s), also about 400 centipoise (0.4 Pa-s) to about 10,000 centipoise (10 Pa-s) ), as an alternative from about 800 centipoise (0.8 Pa-s) to about 6,000 centipoise (6 Pa-s) at a temperature of about 75 ° F (23.9 ° C) to about 500 ° F (260 ° C), as an alternative of about 100 F (37.8 C) at approxMrradamenibétó'iiíiG ^^ EA INDUSTRIAL (204.4 °), as a native alter from approximately 200 ° F (93.3 ° C) to approximately 350 ° F (176.7 ° C). As the cutting speed increases from about 3 sec-1 to about 300 sec-1, as an alternative from about 10 sec-1 to about 100 sec-1, the CPBC may show

<td>weight loss</td><td>cut </td><td colspan="2">at a temperature of</td><td colspan="2">approximately</td>

<td>75 ° F (23.9 ° C)</td><td colspan="2">to approximately</td><td>500 ° F</td><td>(260 ° C),</td><td>how</td>

<td>alternative of</td><td colspan="2">approximately</td><td>100 ° F</td><td>(37.8 ° C)</td><td>to</td>

<td>approximately</td><td>400 ° F</td><td>(204.4 ° C),</td><td>how</td><td>alternative</td><td>of</td>

<td>approximately</td><td>200 ° F (</td><td>93.3 ° C) a</td><td colspan="3">about 300 ° F</td>

<td>(148.9 ° C). In</td><td>this</td><td>document,</td><td colspan="2">behavior</td><td>of</td>

<td colspan="2">slimming cut</td><td>it means</td><td>to</td><td>viscosity</td><td>of the</td>

material that decreases with increasing cutting speed.

In one embodiment, CPBC has a lower flow rate at a temperature of about 75 ° F (23.9 ° C) to about 500 ° F (260 ° C), as an alternative from about 100 ° F (37.8 ° C) to about 400 ° F (204.4 ° C), alternatively from about 200 ° F (93.3 ° C) to about 350 ° F (176.7 ° C).

A CPBC of the type described herein can be further characterized as thermally stable at temperatures equal to or less than about 500 ° F (260 ° C), alternatively about

<img file="MX344584B_D0020.tif" />

FROM THE OWNER

INDUSTRIAL approximately 450 ° F (232.2 ° C), also approximately

75 ° F (23.9 ° C) to approximately 400 ° F (204.4 ° C). Thermal stability herein refers to the ability of CPBC to produce viscosity and maintain solubility in brines in the described temperature ranges.

In some modalities, the CPBC may also be made of solid materials. Hereinafter a CPBC comprising brine, a CP and solids all of the type described herein is referred to as solid containing CPBC (SCPBC). These solids can be particulate matter added to CPBC to alter or improve the properties of CPBC (eg, loss of control liquid, increased density). Examples of such solids suitable for use in the description include, but are not limited to calcium carbonate, iron carbonate, magnesium carbonate, barite, hematite, ilmenite, or combinations thereof.

In one embodiment, solids may be present in the SCPBC in an amount of about 1 lb / BBl (0.002853 kg / L) of about 400 lb / BBl (1.1412 kg / L), also about 20 lb / BBl (0.05706 kg / L) at about 200 lb / BBl (0.5706 kg / L), as an alternative from about 50 lb / BBl (0.14265 kg / L), to about 100 lb / BBl (0.2853 kg / L).

In one embodiment, the SCPBC has a brine present in an amount of from about 53 vol.% To about 99.6 vol.% Based on the total volume of the SCPBC, also from about 74 vol.% To about 98 vol.%, Also from about 85 vol.% to about 95 vol.%.

In one embodiment, a CP, brine, and calcium carbonate are contacted to form an SCPBC. For example the CP may consist of poly-DADMAC which is present in an amount from about 3 lb / BBl (0.008559 kg / L) to about 15 lb / BBl (0.042795 kg / L), the brine may consist of a chloride solution calcium present in an amount of about 55 vol.% to about 98 vol.% and the solids may consist of calcium carbonate present in an amount of about 10 lb / BBl (0.02853 kg / L), at about 380 lb / BBl (1,08414 kg / L). In such an embodiment, the resulting SCPBC can be characterized by the formation of a network structure that exhibits improved suspension capacity.

In another embodiment, the CP may consist of poly-DADMAC which is present in an amount of about 3 lb / BBl (0.008559 kg / L), to about 15 lb / BBl (0.042795 k / L), the brine may consist of a calcium chloride and calcium bromide solution present in a quantity of

IMPI ^

MÍXICAN INSTITUTE *)

OF THE PROHHUI.)

INDUSTRIAL

<img file="MX344584B_D0021.tif" />

<img file="MX344584B_D0022.tif" />

about 55 vol.% at approximate eriTirft &amp; ExicsMjil ¹ Say THE PROPERTY

INIXJSTRIAL solids may consist of calcium carbonate present in an amount of about 10 lb / BBl (0.02853 kg / L) to about 380 lb / BBl (1.08414 kg / L).

In another embodiment, the CP may consist of poly-DADMAC which is present in an amount of from about 3 lb / BBl (0.008559 kg / L) to about 15 lb / BBl (0.042795 kg / L), the brine may consist of a solution calcium bromide present in an amount of about 55 vol.% to about 98 vol.% and the solids may consist of calcium carbonate present in an amount of about 10 lb / BBl (0.02853 kg / L) to about 380 lb / BBl (1.08414 kg / L).

In another embodiment, the CP may consist of poly-DADMAC, which is present in an amount from about 3 lb / BBl (0.008559 kg / L), to about 15 lb / BBl (0.042795 kg / L), the brine may consist of a solution of calcium chloride, calcium bromide and zinc bromide that is present in an amount of about 55 vol.% to about 98 vol.% and the solids may consist of calcium carbonate present in an amount of about 10 lb / BBl (0.02853 kg / L), at about 380 lb / BBl (1.08414 'kg / L).

Contact of solids of the type described herein with CPBC may be made by any means

<img file="MX344584B_D0023.tif" />

mixed or combined using a mixer, stirrer, stirrer, and the like. In one embodiment, the SCPBC is formed by contacting a CP with a brine for a period of time sufficient to allow dissolution of the CP in the brine and the formation of a homogeneous mixture. Solids can be added to the homogeneous mixture to form SCPBC. In an alternative embodiment the CP, brine, and solids are simultaneously contacted to form a mixture that can then be mixed / stirred for a period of time sufficient to form a homogeneous mixture. Mixing conditions (mixing speed, time period, etc.) can be determined by one skilled in the art with the help of this disclosure.

SCPBC can be characterized by an increase in

<td>capacity of</td><td>suspension,</td><td>in comparison with</td><td colspan="3">a composition</td>

<td>similar of</td><td>Another way</td><td>prepared for lack</td><td>of a</td><td>CP.</td><td>The</td>

<td>capacity of</td><td>suspension</td><td>SCPBC</td><td>indicates</td><td>by</td><td>the</td>

sedimentation of the solids and / or a phase separation, which is evidenced by the formation of a clear brine layer on the surface of the fluid. The degree of phase separation can be determined by mixing solids (eg, calcium carbonate) and a CPBC in a clear tube to form the SCPBC, and then allow the solids to settle as the solids settle into

<img file="MX344584B_D0024.tif" />

Saw.

\ no me E&gt; £ THE INDUSTRIAL PHOPISPAD the SCPBC, clear fluid is the tie:

Look near the top of the tube. For example, a tube 10 containing the SCPBC after mixing and allowing it to settle may appear as shown in the figure.

1.

Referring to Figure 1, tube 10 has suspended solids 30 clear fluid 20.

The degree of phase separation is calculated by dividing the height of the clear fluid (i.e., h3 or hltotal of the liquid (i.e., hl) and multiplying by 100%.

In one embodiment, the

SCPBC has a degree of phase separation of about

0% approximately

60%, as an alternative of about

30%, as an alternative of about

2% approximately

10% after a period of time from two hours to about 14 days, alternatively from about 4 hours to about 7 days, alternatively from about 6 hours to about 24 hours.

In one embodiment, an SCPBC exhibits the behavior of a non-Newtonian fluid as previously described herein. In one embodiment, at a cutting speed of about 0.1 sec-1 to about 10 sec-1, alternatively from about 0.5 sec-1 to about 5 sec-1, alternatively from about 1 sec-1 to about 2 sec -1 SCPBC can have a viscosity of around

100 centipoise (0.1 Pa-s) to about 40,000 cenJijMísjP ^ ($ ^&gt; ^ 1 ^ MEXICAN INSTITUTE, and \

Ot 1.A PROPERTY% ** e¿Sa4íí¿j / also about 400 centipoise (0.4 Pa-s) to ^ Ws rüyüO't) centipoise (10 Pa-s), as an alternative of 9Ü0 centipoisé '*' ”C0 ”.T⁼'' Pa-s) at about 6,000 centipoise (6 Pa-s) at a temperature of about 75 ° F (23.9 ° C) at about 500 ° F (260 ° C), as an alternative of about 100 ° F ( 37.8 ° C) at approximately 400 ° F (204.4 ° C), as an alternative from approximately 200 ° F (93.3 ° C) to approximately 350 ° F (176.7 ° C). As the cutting speed is increased from 3 sec-1 to about 300 sec-1, as an alternative from about 10 sec-1 to about 100 sec-1, SCPBC can show

<td>a behavior</td><td>of</td><td colspan="2">weight loss</td><td>cut</td><td>to</td><td>a</td>

<td>Temperature of</td><td colspan="2">approximately</td><td>75 ° F</td><td> (23.9</td><td>° C)</td><td>to</td>

<td colspan="2">about 500 ° F</td><td>(260 ° C),</td><td>how</td><td colspan="2">alternative</td><td>of</td>

approximately 100 ° F (37.8 ° C) to approximately 400 ° F (204.4 ° C), as an alternative from approximately 200 ° F (93.3 ° C) to approximately 300 ° F (148.9 ° C).

In one embodiment, SCPBC comprising CP, brine, and solids of the type described herein (eg, calcium carbonate) are effective as a fluid loss control agent. Specifically, SCPBC can have a fluid loss filtering volume of about 0 ml to about 60 ml, or

<img file="MX344584B_D0025.tif" />

<img file="MX344584B_D0026.tif" />

Df THE PMOPfEDAÍ?

INDUSTRIAL

<img file="MX344584B_D0027.tif" />

about 0 mi to about 30 n mi to about 20 mi after a time period of about 30 minutes, as determined in accordance with API RP 13B.

The CPBC and / or SCPBC comprising a CP of the type described herein can be used in oil field operations. In particular, the CPBC and / or SCPBC can be placed in a well and used for well service in accordance with procedures known to those of skill in the art. For example, CPBC and / or SCPBC can be used to drill, prepare, complete, maintain, or improve a well for hydrocarbon production in an underground formation penetrated by the well. In another embodiment, the CPBC and / or SCPBC are prepared at the well site. For example the CP can be mixed with other CPBC and / or SCPBC components on the surface and then placed below the well. As an alternative, CPBC and / or SCPBC is prepared off-site and transported to the site of use before being placed below the bore.

In one embodiment, CPBCs can be used as termination fluids, working fluids, spacer fluids, and fluid plugs. For example, as completion fluids, CPBC can be placed in the well to facilitate final operations prior to initiation of the

<img file="MX344584B_D0028.tif" />

production. The CPBC can be used to have hardware below the hole lose integrity, without damaging the formation or end of production components. The CP can be included in the CPBC before the fluid is placed below the orifice in a modality of

<td>stream</td><td colspan="3">simple. As an alternative,</td><td>the</td><td>CP</td><td>can be</td>

<td colspan="2">mixed with</td><td>the others</td><td>components of</td><td>the</td><td>CPBC</td><td>during the</td>

<td>placement</td><td>in</td><td>the hole</td><td>for example in</td><td>a</td><td colspan="2">process two</td>

<td>currents</td><td>in</td><td>where a</td><td>current consists</td><td>of</td><td>CP and</td><td>A second</td>

stream consists of brine. In one embodiment, the brine and CP are introduced into the well in separate streams and the CPBC is formed below the hole. In one embodiment, the CP is placed below the hole where it is contacted with a natural brine present in the formation and forms a CPBC in situ.

The relatively low viscosity produced by CPBC at high cutting speeds as described earlier in this document suggests that fluid can flow in the tube and ring without the use of excessive friction pressures. Thus, the low viscosity of CPBC at high cutting speeds can allow for easy pumping of the composition and can facilitate its use as a circulation fluid during well drilling. At low cutting speeds the high viscosity of CPBC can allow the composition to function as a fluid. Like fluids

IMPI an industrial job agent, CPBC can be used

<img file="MX344584B_D0029.tif" />

to repair or stimulate a production existence or to replace, prolong, or increase the production of hydrocarbons.

In one embodiment the SCPBC can be used as drilling fluids, gravel packing fluids, fabrication fluids, fluid loss control fluids, lost circulation control fluids, suspending agents, or combinations thereof. For example, as a SCPNC drilling fluid can be circulated low through a hollow drill rod and out through a drill bit attached to this while rotating the drill rod to drill the bore. Drilling fluid can be flowed behind the surface via the annular space between the drill string and the bore to deposit the filter cake on the walls of the bore and make drilling cuts to the surface. The CP can be included in SCPBC before the fluid is placed below the orifice in a single stream mode. As fluid loss controls agents, SCPBC can be used to control or decrease fluid loss through filtration and / or formation absorption (for example, excessive fluid loss from the filter cake in the underground formation). The impi loss

ΟΙβτιτυτο &amp; Ιχ ^ ΑΛ M THE INDUSTRIAL currency

<img file="MX344584B_D0030.tif" />

frequently occurs in a piercing, it can lead to severe problems. For example, an excessive amount of filter cake can accumulate on the wellbore walls, causing the drill pipe to become loaded and may be difficult to remove from the wellbore.

Furthermore, the relatively high viscosity produced by SCPBC in the low shear stress range as described above is useful for suspending solids and providing control of fluid loss. Similarly for CPBC, the relatively low viscosity produced by SCPBC at high cutting speeds indicates that fluid flow in the pipe and annulus (eg, during fluid circulation) can be achieved without excessive friction pressures.

In certain modalities, the method of using CPBC may also include servicing the well with a well maintenance fluid. In addition, the method may also include fuel extraction from the well after service. As noted, certain modalities have clear advantages in improving the well and can influence well efficiency.

EXAMPLES

The modalities that are generally described, the

<img file="MX344584B_D0031.tif" />

IMPI following examples are given as modality © envPBiBfcii €&gt; u '

DLÍA NttHBIMD INDUSTRIAL the description and to demonstrate the practice and the advantages thereof. It is understood that the examples are provided by way of illustration and are not intended to limit the specification or the claims in any way.

SAMPLE PREPARATION

In the following example, all samples are prepared using the following general procedure, unless otherwise noted. The samples are prepared by mixing brine and a PC using a LR400D general shaker, which is commercially available from Yamato Scientific America Inc. The samples are then allowed to hydrate overnight or longer before analysis. Thereafter, if the samples are grainy in appearance, a final brief agitation of approximately 30 seconds is carried out using a hand mixer, which is commercially available from Braun.

The rheological properties are determined using a Chandler Model 5550 viscometer, with a rotor-bob Rl / Bl configuration. The viscometer is programmed to run a cutoff speed ramp at room temperature (75 ° F / 23.9 ° C) with intervals of 50 ° F (27.8 ° C) and a final temperature of 350 ° F (176.7 ° C). Nitrogen pressure is applied at 320 psi (2206.3 kPa). The ramps include viscosity measurements at rotacXd ^^ j ^ Q ^ i 'F speeds. * WM&gt; Ar. 'RUSTRI AL

<img file="MX344584B_D0032.tif" />

300 rpm. The warm-up period between ramps is * · * “• RKW · approximately 8 minutes. The samples are then kept at test temperature for about 11 minutes during the ramp.

EXAMPLE 1

The solubility, thermal stability and rheological properties of a CP in a CaC12 brine are investigated. The CaC12 salt used is 95% CaC12 mini-pellets commercially available from Cal-Chlor Corp., and the cationic polymer used is a poly-DADMAC, which is commercially available from Northaven Chemical. Sample 1 is prepared using 10.5 lbs / Bbl (0.029957 kg / L) of poly-DADMAC to thicken 11.6 ppg (1.30 kg / L) of CaC12 brine. Specifically, 0.20 g of calcium hydroxide is dispersed in 210 g of deionized water and 140 g of CaC12 salt are added until the liquid becomes transparent. Next, 7.5 g of poly-DADMAC is added slowly and the mixture is stirred for 15 minutes and then allowed to hydrate overnight prior to testing.

Rheological tests are carried out and the results are shown in Figures 2 and 3. Figure 2 is a graph of viscosity as a function of cutting speeds at different temperatures. Referring to Figure 2,

ΙΜΡΪ ^^&gt;

the CP in brine produces viscosities q ^^ u-t ^ lLcAfifé

Say LA FRORIFDAí

INDUSTRIAL approximately 2500 cP (0.02 to 2.5 Pa-s) depending on the cutting speed. At any temperature, the fluid viscosity shows the shear thinning behavior. Figure 3 is a graph of shear stress versus cut speeds at different temperatures. Referring to Figure 3, a slope adjustment is observed at cutting speeds between 10 and 20 sec-1 at all temperatures. This observed fit suggests that the dominant polymer-polymer interactions differ between high and low cutting speeds. The flow index (n ') and the consistency index (K *) are estimated separately, for both the high and low cutting speed regions by curve fitting the data, using a power law model, where the flow index is the slope and the consistency index is the intersection. The results are tabulated in Table 1.

TABLE 1

<td rowspan="2">Temperature (° F)</td><td rowspan="2">Temperature (° C)</td><td colspan="2">Low-cut effort</td><td colspan="2">High cutting effort</td><td rowspan="2">Viscosity (1 sec^-1)</td><td rowspan="2">Viscosity (170 sec¹)</td>

<td>n '</td><td>K '</td><td>n '</td><td>K '</td>

<td> 78</td><td> 25.6</td><td> 0.1964</td><td> 0.0509</td><td> 0.7508</td><td> 0.0125</td><td> 2, 436</td><td> 167</td>

<td> 100</td><td> 37.8</td><td> 0.1865</td><td> 0.0455</td><td> 0.7156</td><td> 0.0106</td><td> 2,179</td><td> 118</td>

<td> 150</td><td> 65.6</td><td> 0.2003</td><td> 0.0278</td><td> 0.7015</td><td> 0.0066</td><td> 1,330</td><td> 68</td>

<td> 200</td><td> 93.3</td><td> 0.2149</td><td> 0.0196</td><td> 0.7010</td><td> 0.0044</td><td> 939</td><td> 45</td>

<td> 250</td><td> 121.1</td><td> 0.2113</td><td> 0.0170</td><td> 0.7006</td><td> 0.0032</td><td> 814</td><td> 33</td>

<td> 300</td><td> 148.9</td><td> 0.3602</td><td> 0.0106</td><td> 0.6844</td><td> 0.0029</td><td> 509</td><td> 27</td>

<td> 350</td><td> 176.7</td><td> 0.3115</td><td> 0.0125</td><td> 0.5949</td><td> 0.0041</td><td> 596</td><td> 24</td>

brine region

NSTITUTO MEXICANO Cl LA INODUSTRIAL RODEPAD TI-lower cut speed suggested that the CP in CaC12 displays suspension capacity even above 350 ° F (176.7 ° C).

EXAMPLE 2

The ability of a CP to thicken CaBr2 and brines

ZnBr2 investigates and compares the behavior of a PC and a CaC12 brine. Three samples, designated samples 2-4 are prepared using 10.5 lb / BBI (0.29957 kg / L) poly-DADMAC to thicken 11.6 ppg (1.39 kg / L) of CaC12 brine, 13.2 ppg (1.58 kg / L) of CaBr2 brine, and 19.2 ppg (2.30 kg / L) of ZnBr2 brine, respectively. All samples are allowed to hydrate overnight before the assay and rheology test is carried out. The results are presented in Table 2.

TABLE 2

<td rowspan="2">Temperature</td><td rowspan="3">Temperature (° C)</td><td>Sample 2</td><td>Sample 3</td><td>Sample 4</td>

<td>Viscosity</td><td>Viscosity</td><td>Viscosity</td>

<td></td><td>(170 sec^-1)</td><td>(170 sec^-1)</td><td>(170 sec^-1)</td>

<td> 78</td><td> 25.6</td><td> 247</td><td> 226</td><td> 265</td>

<td> 100</td><td> 37.8</td><td> 193</td><td> 173</td><td> 166</td>

<td> 150</td><td> 65.6</td><td> 109</td><td> 103</td><td> 78</td>

<td> 200</td><td> 93.3</td><td> 74</td><td> 71</td><td> 50</td>

<td> 250</td><td> 121.1</td><td> 52</td><td> 51</td><td> 36</td>

<td> 300</td><td> 148.9</td><td> 37</td><td> 38</td><td> 28</td>

<td> 350</td><td> 176.7</td><td> 26</td><td> 27</td><td> 22</td>

Referring to Table 2, samples 2-4 show comparable viscosities throughout the ranges.

<img file="MX344584B_D0033.tif" />

research temperature. Normal weight loss is observed for each sample during heating to 350 ° F (176.7 ° C) and there is no indication that polymer entanglement or precipitation is observed. After testing, samples 2-4 are cooled to room temperature and the recovered samples are clear, odorless viscous solutions.

EXAMPLE 3

The ability of a synthetic anionic polymer and a nonionic polymer to viscosify a brine is compared to that of a PC. Three samples, samples designated 5-7, are prepared. Sample 5 comprises poly-DADMAC and is similar to Sample 1 of Example 1. Sample 6 is prepared with 5 lb / BBI (0.014265 kg / L) of acrylamide-AMPS copolymer (i.e. a synthetic anionic polymer), which is available commercially Drilling Specialties Company. Specifically, 140 g of CaC12 is added to 210 g of deionized water and stirred until the fluid becomes transparent. Next, 3.57 g of acrylamide-AMPS is added slowly until the acrylamide-AMPS copolymer is completely dissolved. Sample 7 is prepared with 2.5 lb / BBI (0.007133 kg / L) of NATROSOL HHX, which is a non-ionic copolymer of hydroxyethyl cellulose (HEC) commercially available from Hercules Incorporated. Specifically, 2 g of HEC is added to 280 ml of 11.6 ppg (1.39 kg / L) of

<img file="MX344584B_D0034.tif" />

GIVE INDUSTRIAL PROPERTY final concentrations of the brine are the same in samples 5-7. The samples are left to hydrate overnight and then rheological tests are performed. The results are shown in Figure 4.

Referring to Figure 4, the viscosity of samples 6 and 7 at 100 ° F (37.8 ° C) is 189 cp (102 sec-1) and 460 cp (102 sec-1), respectively. The acrylamide-AMPS copolymer is less efficient in thickening the CaC12 brine, since it produces a viscosity less than twice the polymer load. Sample 7 produces a higher viscosity than Sample 5 only only above 205 ° F (96.1 ° C). The low viscosity observed for sample 7 at 240 ° F (115.6 ° C) is typical of HEC performance, which typically limits its usefulness at temperatures below 240 ° F (115.6 ° C). The viscosity of sample 6 is higher than that of sample 5 throughout the test. However, the acrylamide-AMPS copolymer gels during cooling, potentially causing formation damage and restricting fuel and gas production. In contrast, the CP used in Sample 5 demonstrates the ability to thicken CaC12 brine up to 350 ° F (176.7 ° C) and is capable of maintaining its solubility after

AND

UTO MEXICANO c '.a rwraxiD INWjTHML

<img file="MX344584B_D0035.tif" />

exposure to temperature ranges.

EXAMPLE 4

CPBC's ability to suspend solids is investigated. The CP used is FLOQUAT FL3249, which is a polyamine commercially available from SNF Floerger. Sample 8 is prepared by adding 6 g of FLOQUAT FL3249 in 81 g of deionized water. Next, 0.1 g of calcium hydroxide is added to adjust the pH to 8.5 and 56 g of CaC12 is added so that the final brine density reaches 11.6 ppg (1.39 kg / L). The fluid is cooled to room temperature. 13.4 g of CaCO3 is then added to 60 ml of the fluid and stirred until homogeneous. CaCO3 is precipitated with magnesia, which is commercially available from Fisher Scientific. Rheological tests of the sample are then carried out and the results are presented in Table 3.

TABLE 3

<td rowspan="3">Temperature (° F)</td><td rowspan="3">Temperature (° C)</td><td>Sample 8</td><td>Sample 8</td>

<td>Viscosity</td><td>Viscosity</td>

<td>(2 sec^-1)</td><td>(170 sec^-1)</td>

<td> 78</td><td> 25.6</td><td> 648</td><td> 85</td>

<td> 100</td><td> 37.8</td><td> 696</td><td> 67</td>

<td> 150</td><td> 65.6</td><td> 768</td><td> 46</td>

<td> 200</td><td> 93.3</td><td> 576</td><td> 36</td>

<td> 250</td><td> 121.1</td><td> 432</td><td> 16</td>

<td> 300</td><td> 148.9</td><td> 456</td><td> 15</td>

<td> 350</td><td> 176.7</td><td> 504</td><td> 15</td>

During heating sample 8 shows normal thermal thinning. In each temJ ^ - ^^ J ^ ni THE INDUSTRIAL PROFIÍDAO

<img file="MX344584B_D0036.tif" />

The sample exhibits considerable shear thinning, as shown by the contrast between the viscosity sec-1 and

170 sec-1.

Relatively high viscosity at low cutting speed indicates suspension capacity.

The suspension capacity is further confirmed after Sample 8 cools. Cooled Sample 8 is homogeneous and there is no evidence of precipitation or sedimentation of calcium carbonate.

EXAMPLE 5

The theological properties of a PC in brine CaC12 are investigated, and compared to a PC in brine CaC12 containing CaCO3. Sample 9 is prepared from 10.5 lb / BBI (0.029957 kg / L) of poly-DADMAC in 11.6 ppg (1.39 kg / L) of CaC12 in a similar manner to that used in Example 1. The pH of the fluid is adjusted to 8.4 using 0.5 lb / BBI (0.001427 kg / L) of calcium hydroxide. Theological tests are carried out and the results are shown in Table 4 and Figure 5, which is a graph of viscosity as a function of cutting speed at 350 ° F (176.7 ° C).

<img file="MX344584B_D0037.tif" />

TABLE 4

IMPI • RSTTTUT · MUICAA'O OS LA FROHÍDAO inbustuiai

<td>Temperature (° F)</td><td>Temperature (° C)</td><td>n '</td><td>K '</td><td>Viscosity (1 sec^-1)</td><td>Viscosity (40 according to¹)</td><td>Viscosity (100 sec^-1)</td><td>Viscosity (170 sec^-1)</td>

<td> 78</td><td> 25.6</td><td> 0.7707</td><td> 0.0128</td><td> 614</td><td> 264</td><td> 214</td><td> 189</td>

<td> 100</td><td> 37.8</td><td> 0.7677</td><td> 0.0090</td><td> 429</td><td> 182</td><td> 147</td><td> 130</td>

<td> 150</td><td> 65.6</td><td> 0.7786</td><td> 0.0045</td><td> 216</td><td> 96</td><td> 78</td><td> 69</td>

<td> 200</td><td> 93.3</td><td> 0.7605</td><td> 0.0033</td><td> 158</td><td> 65</td><td> 53</td><td> 46</td>

<td> 250</td><td> 121.1</td><td> 0.7655</td><td> 0.0024</td><td> 113</td><td> 48</td><td> 38</td><td> 34</td>

<td> 300</td><td> 148.9</td><td> 0.7573</td><td> 0.0019</td><td> 92</td><td> 38</td><td> 30</td><td> 26</td>

<td> 350</td><td> 176.7</td><td> 0.7839</td><td> 0.0014</td><td> 69</td><td> 31</td><td> 25</td><td> 23</td>

The results show that at each temperature, sample 9 displays a higher viscosity at the lower cutting speed of 1 sec-1 than at the higher cutting speed of

170 sec-1.

Furthermore, as the temperature increases to 350 ° F (176.7 ° C), the viscosity of sample 9 decreases.

Therefore, the sample is capable of maintaining its shear thinning behavior at temperatures up to 350 ° F (176.7 ° C).

Sample is prepared using my sample

9, by adding 20 lb / BBI (0.05706 kg / L) of CaCO3 powder. Rheological tests are then performed and the results are presented in Table 5.

TABLE 5

<td>Temperature (° F)</td><td>Temperature (° C |</td><td>n '</td><td>K '</td><td>Viscosity (1 sec^-1)</td><td>Viscosity (40 sec^-1)</td><td>Viscosity (100 sec^-1)</td><td>Viscosity (170 sec^-1)</td>

<td> 78</td><td> 25.6</td><td> 0.6809</td><td> 0.0244</td><td> 1.170</td><td> 361</td><td> 269</td><td> 227</td>

<td> 100</td><td> 37.8</td><td> 0.6373</td><td> 0.0221</td><td> 1.057</td><td> 277</td><td> 199</td><td> 164</td>

<td> 150</td><td> 65.6</td><td> 0.5321</td><td> 0.0214</td><td> 1.024</td><td> 182</td><td> 119</td><td> 93</td>

<td> 200</td><td> 93.3</td><td> 0.4525</td><td> 0.0243</td><td> 1.161</td><td> 154</td><td> 93</td><td> 70</td>

<td> 250</td><td> 121.1</td><td> 0.4146</td><td> 0.0249</td><td> 1.192</td><td> 138</td><td> 80</td><td> 59</td>

<td> 300</td><td> 148.9</td><td> 0.4063</td><td> 0.0233</td><td> 1.117</td><td> 125</td><td> 73</td><td> 53</td>

<td> 350</td><td> 176.7</td><td> 0.3837</td><td> 0.0249</td><td> 1.190</td><td> 123</td><td> 70</td><td> 50</td>

The results show that at temperlí®SKSÍSSe ^ ® (fi £

INDUSTRIAL addition of CaCO3 (sample 10) has a greater effect on the low cut speed of 1 sec-1 than on high cut speeds of 170 sec-1. The results suggest that Sample 10 is more shear thinning than Sample 9. Without wishing to be limited by theory, there may be a relatively weak interaction between poly-DADMAC and CaCO3. Sample 10 shows expected thermal thinning at high cutting speeds of 170 sec-1 and its viscosity at low cutting speeds of 1 sec-1 is relatively stable between 78 ° F (25.6 ° C) and 350 ° F (176.7 ° C) . The results suggest the interaction between poly-DADMAC and suspended CaCO3 is strong enough to resist the effects of increased temperature but could be mechanically interrupted. Furthermore, the ability of sample 10 to maintain solids (CaCO3) in suspension is maintained throughout this temperature range.

A static aging test is also performed

<td colspan="3">in sample 10</td><td>through</td><td>the</td><td>monitoring</td><td>of the</td><td>grade</td><td>of</td>

<td>separation</td><td>of</td><td>phase</td><td>around</td><td>of</td><td>168 hours</td><td>to</td><td colspan="2">temperature</td>

<td>environment</td><td> (75°</td><td>F / 23.9</td><td>° C) and in</td><td> 250</td><td>° F (121.1</td><td>° C).</td><td>10 mi</td><td>of</td>

<td>servings</td><td>of</td><td colspan="2">sample 10 is</td><td colspan="2">placed in</td><td>two</td><td>jars</td><td>of</td>

<td>glass and</td><td>I know</td><td>seal</td><td colspan="2">A jar</td><td>is placed</td><td>to</td><td colspan="2">temperature</td>

environment and another jar is placed in an oven at 250 ° F (121.1 ° C).

The results are shown in the

IMPI

MEXICAN INSTITUTE -f .¾ table that is a graph of the fas separation% to ... a ....... 7, 5 ° F (2.3-JL · ___ ° C) as a function of time.

TABLE 6

<td>Time (hours)</td><td>% sedimentation at 75 ° F (23.9 ° C)</td><td>% of sedimentation a 250 ° F (121.1 ° C)</td>

<td> 24</td><td> 8%</td><td> 3%</td>

<td> 48</td><td> 21%</td><td> 3%</td>

<td> 72</td><td> 25%</td><td> 3%</td>

<td> 96</td><td> 29%</td><td> 3%</td>

<td> 168</td><td> 34%</td><td> 3%</td>

The results demonstrate that during the experiment, there was no evidence of particle sedimentation. CaCO3 is kept in suspension in sample 10. There is evidence of precipitate in sample 10 where clear brine separates from the surface as a separate layer. In the 168 hours of static aging tests at 250 ° F (121.1 ° C), only 3% of the sample of 10 separates to the surface like clear brine.

EXAMPLE 6

The ability of a PC to prevent fluid loss in CaC12 brine comprising blows is investigated. Sample 11 is prepared from 10.5 lb / BBI (0.029957 kg / L) of polyDADMAC in 11.6 ppg (1.39 kg / L) of CaC12 brine and 25 lb / BBI (0.071325 kg / L) of CaCO3 using the similar procedure as described above . Loss experiments

MIXICANC INSTITUTE

PROPERTY fluid is conducted at a temperature of 250 F (121.1^ΝΟ'' Φ)^ΑΙ

IMPI 500 psi nitrogen pressure (3447.T Jera), intercourse is described in API RP-13B. The results are shown in Table 7 and Figure 7.

TABLE 7

<td>Time (minutes)</td><td>Filtered volume (mi)</td>

<td> 3</td><td> 4</td>

<td> 5</td><td> 6</td>

<td> 10</td><td> 8</td>

<td> 15</td><td> 9</td>

<td> 20</td><td> 10.4</td>

<td> 30</td><td> 12.2</td>

Results show that a total of 12 ml of filtrate is collected in the 30 minute test period, demonstrating the ability of poly-DADMAC to prevent fluid loss when used in conjunction with calcium carbonate. After testing, sample 10 is removed and there is no evidence of sedimentation or development of cohesive filter cake on the surface of the filter paper.

EXAMPLE 7

The rheological properties of a CP in CaBr2 brine are investigated. Sample 12 is prepared from 10.5 lb / BBI (0.029957 kg / L) of poly-DADMAC in 14.2 ppg (1.70 kg / L) of CaBr2 using a procedure similar to that described above, the pH of the sample was adjusted to approximately 8.2 and tests Rheologicals are performed. The

<img file="MX344584B_D0038.tif" />

IMPI

, .., JNSTITUTO MEXICANO results are shown in Table 8 and Figure 8 is a graph of viscosity versus shear rate and Figure 9 is a graph of viscosity as a function of time at 350 ° F (176.7 ° C).

TABLE 8

<td>Temperature (° F)</td><td>Temperature (° C)</td><td>n '</td><td>K '</td><td>Viscosity (one seg^-1)</td><td>Viscosity (40 sec^-1)</td><td>Viscosity (100 sec^-1)</td><td>Viscosity (170 sec^-1)</td>

<td> 78</td><td> 25.6</td><td> 0.7175</td><td> 0.0121</td><td> 579</td><td> 204</td><td> 158</td><td> 136</td>

<td> 100</td><td> 37.8</td><td> 0.6983</td><td> 0.0108</td><td> 519</td><td> 170</td><td> 129</td><td> 110</td>

<td> 150</td><td> 65.6</td><td> 0.6628</td><td> 0.0080</td><td> 385</td><td> 111</td><td> 82</td><td> 68</td>

<td> 200</td><td> 93.3</td><td> 0.6065</td><td> 0.0081</td><td> 388</td><td> 91</td><td> 63</td><td> 51</td>

<td> 250</td><td> 121.1</td><td> 0.6227</td><td> 0.0062</td><td> 297</td><td> 74</td><td> 52</td><td> 43</td>

<td> 300</td><td> 148.9</td><td> 0.6058</td><td> 0.0057</td><td> 272</td><td> 64</td><td> 44</td><td> 36</td>

<td> 350</td><td> 176.7</td><td> 0.6387</td><td> 0.0041</td><td> 195</td><td> 52</td><td> 37</td><td> 31</td>

The results demonstrate that the rheological behavior of poly-DADMAC in CaBr2 brine is similar to polyDADMAC in CaC12 brine, with the shear thinning behavior maintained above 350 ° F (176.7 ° C). In addition, the thermal stability of sample 12 was tested by maintaining the sample at a cut speed of 170 sec-1 and a temperature of 350 ° F (176.7 ° C) for four hours. The results are shown in Figure 9. The results demonstrate that the viscosity of sample 12 decreases from approximately 29 cp (0.029 Pa-s) to approximately 24 cp (0.024 Pa-s) indicating the thermal stability of sample 12.

IMPIOUS?,?

MEXICAN INSTITUTE ot la raoruDAO

INDUSTRIAL ----- 38 in brine 7.nRr7 that EXAMPLE 8

The rheological properties of a CP investigate. Sample 13 is prepared from 10.5 lb / BBI (0.029957 kg / L) of poly-DADMAC in 19.2 ppg (2.30 kg / L) of ZnBr2 and rheological tests are performed. The results are presented in Table 9.

TABLE 9

<td>Temperature ('F)</td><td>Temperature (° C)</td><td>n '</td><td>K '</td><td>Viscosity (one seg^-1)</td><td>Viscosity (40 seg^-1)</td><td>Viscosity (100 sec *¹)</td><td>Viscosity (170 sec *¹)</td>

<td> 80</td><td> 26.7</td><td> 0.8390</td><td> 0.0127</td><td> 607</td><td> 335</td><td> 289</td><td> 265</td>

<td> 150</td><td> 65.6</td><td> 0.9083</td><td> 0.0026</td><td> 126</td><td> 90</td><td> 82</td><td> 78</td>

<td> 200</td><td> 93.3</td><td> 0.9218</td><td> 0.0016</td><td> 75</td><td> 56</td><td> 52</td><td> 50</td>

<td> 250</td><td> 121.1</td><td> 0.9619</td><td> 0.0009</td><td> 44</td><td> 38</td><td> 37</td><td> 36</td>

<td> 300</td><td> 148.9</td><td> 0.9599</td><td> 0.0007</td><td> 35</td><td> 30</td><td> 29</td><td> 28</td>

<td> 350</td><td> 176.7</td><td> 0.9989</td><td> 0.0005</td><td> 22</td><td> 22</td><td> 22</td><td> 22</td>

EXAMPLE 9

The rheological properties of a higher solids load are investigated.

from 7 lb / BBI (0.019971 kg / L) from (1.39

CaCO3

200 ° F

CP in brine CaC12 in

Sample 14 is prepared to poly-DADMAC in 11.6 ppg kg / L) of CaC12 brine at 78 lb / BBI (0.222534 kg / L) of (93.3 ° C), 300 ° F (148.9 ° C) and 400 ° F (204.4 ° C). The results are shown in Figure 10.

Results suggest that poly-DADMAC appears to interact synergistically with suspended solids

This interaction results in increased viscosity and slimming characteristics.

<img file="MX344584B_D0039.tif" />

MiXiCAHO

JHDUSTMIAl are kept above 400 ° F (204.4 ° C).

While modalities of description have been shown and described, their modifications can be made without departing from the essence and teachings of the description. The modalities described in this document are exemplary only, and are not intended to be limiting. Many variations and modifications of the description described herein are possible and are within the scope of the description. When numerical ranges or limitations are expressly stated, such as fast ranges or limitations should be understood to include interactive ranges or limitations of magnitude that fall within expressly stated ranges or limitations (eg, from about 1 to about 10 includes, 2 , 3, 4, etc., greater than 0.10 include 0.11, 0.12, 0.13, etc.) For example, when a numerical interval with a lower limit, RL, and an upper limit, RU, described, any number that falls within the range is specifically described. In particular, the following numbers within the range are specifically described: R = RL + k * (RU-RL), where k is a variable ranging from 1 percent to 100 percent with an increase of 1 percent, is say, k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, ... 50

IMPI percent, 51 percent, 52 percent,. ^c

INDUSTRIAL

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percent, 97 percent, 98 percent, .99 percent, or

100 percent. On the other hand, any numerical range defined by two numbers of R as defined above is also specifically described. The use of the term optionally with respect to any element of a subject claim is required, alternatives have is understood to mean that the element or alternatively is not required. Both are intended to be within the scope of the claim. The use of broader terms such as understands, includes has etc., should be understood to provide support for shorter terms such as

<td>consists of consists</td><td colspan="2">essentially</td><td>of understands</td>

<td>substantially of, etc.</td><td></td><td></td><td></td>

<td>Consequently, the</td><td>scope of</td><td>the</td><td>protection I don't know</td>

<td>limits by description</td><td>what figure</td><td>plus</td><td>up but only</td>

limited by the claims that follow, which scope includes all the equivalents of the subject matter of the claims. Each and every claim is incorporated into the specification as an embodiment of the present disclosure. Therefore, the claims are a more detailed description and add to the modalities of the present description. Discussion of a reference is not an admission that it is the prior art to the present

IMPI iNsrrnrro mlxicaao

DE LA R »OMED» r&gt;

reference qqe 'pwwa description, especially any

<img file="MX344584B_D0041.tif" />

a post date after the date ^ 'tlVÍ! The nature of this request. The descriptions of all patents, patent applications, and publications cited in this document are incorporated by reference, to the extent that they provide exemplary, procedural, or other supplemental details to those set forth herein.

Λ í

<img file="MX344584B_D0042.tif" />

Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as property: