Untitled record

Full description

Sister Ar'a's background

The present invention relates to methods of drilling through non-reservoir and reservoir sections of subterranean formations during hydrocarbon recovery operations, and more specifically the invention relates, in one non-exclusive embodiment, to using aqueous cement-forming fluids

<p dir="rtl">5 Cement-forming aqueous fluids of relatively high density contain components that inhibit or prevent fluid loss into the subterranean formation.</p>

Drilling fluids are classified into water-based silts and oil-based silts. Drilling fluids are used to drill long horizontal and vertical sections of non-reinforced sections of a borehole. Water-based drilling fluids are formulated with water, a polymer required to increase the viscosity to hold

<p dir="rtl">10 trimers and to control fluid loss, monovalent and multivalent salts to inhibit scaling, various bridging materials and weighting materials (barium sulfate, micronized barite, hausmannite, ilmenite, manganese tetroxide, hematite, and other particles). Soft, dense) for the preferred clay weight. Large amounts of weighing agents are usually required to balance the clay weight against the formation pressure.</p>

<p dir="rtl">15 In heavy fluids (more than about 14 lbs per gallon down to about 20 lbs per gallon; Equivalent to about 1.7 to about 2.4 kg/L), large amounts of weighing agents make dispersibility of other fluid components, especially fluid loss additives, difficult.</p>

Drilling fluids are special fluids configured exclusively for drilling through the reservoir portion of an underground formation. Reasons for using specially prepared drilling fluids include, but are not limited to (1) drilling

<p dir="rtl">20 Successful storage area, usually a long horizontal drying hole, (2) minimize damage to the area near the wellbore and maximize ultimate production of exposed areas, and (3) facilitate completion</p>

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The necessary well. Completing a well may involve complex procedures. Typically, drilling fluids are similar to completion fluids. Drilling fluids can be brine containing only selected solids from appropriate particle size ranges (for example, salt crystals or calcium carbonate) and polyart. Typically, the additives required to control leaching are

<p dir="rtl">5 Loading the cuttings into the drilling fluid. As noted, drilling fluids can contain leaching control additives to inhibit or prevent loss of drilling fluid into cavitated areas of the permeable formation. Fluid loss includes unwanted leakage of the fluid phase of a drilling fluid containing solid particles and complete loss of fluid into the formation die without any return. The resulting accumulation of solids or filter cake against the drill hole can be unfavorable, as can penetration of filter cake into the formation. It may result in removal</p>

<p dir="rtl">10 The filter cake, which must sometimes be forced out, can cause irreparable physical damage to an area near the wellbore of the reservoir. Fluid loss additives are used to control the process and avoid possible damage to the reservoir, especially in the area near the wellbore. Specially prepared fluids may be used to place near the reservoir and form a seal against fluid loss. This fluid can be different from drilling fluid and is often referred to as “sealing” or “lost bead.”</p>

.circulation pill 15

Subterranean formations with naturally occurring characteristics appear problematic because fractures exacerbate unwanted leakage of the fluid portion of the drilling fluid into the formation. However, lost circulation fluid can be a major challenge when drilling through naturally fractured carbonate, sandstone, etc. formations.

<p dir="rtl">20 Some of the lost energy fluids are converted to gel, such as by gelling polymers and optionally cross-linking the resulting polymers. However, it is important to avoid premature gel formation, and it is also important that the gel finally has sufficient viscosity and resistance to achieve the goal of inhibiting or preventing fluid loss. Existing commercial displays have insufficient operating power; Examples include, but are not limited to, commercial LCM (lost circulation material) technology</p>

<p dir="rtl">25 Based on preventing the leakage of polymer resin, thixotropic slurry, or fluid loss pill.</p>

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Therefore, it is preferable to discover a drilling fluid or sealant, drilling fluid or other fluid that has a relatively low viscosity in the drill pipe and a high dispersibility in heavy fluids (more than about 14 pounds per gallon up to about 20 pounds per gallon); Equivalent to about 1.7 to about 2.4 kilograms per liter (but the viscosity increases after a short period of shaking the drill bit and inhibits or prevents leaching

<p dir="rtl">5 fluid to formation.</p>

US Patent 20090253596A1 relates to aqueous, viscoelastic fluids used during hydrocarbon recovery operations, and more specifically relates, in one non-exclusive embodiment, to methods and additives for controlling fluid loss therein.

US patent 20140246198A1 relates to the field of producing crude oil or natural gas from

<p dir="rtl">10 Subterranean formations. More specifically, US Patent 20140246198A1 relates to increasing the viscosity of a well fluid acidifying a subterranean formation, e.g., matrix or acidifying fracture carbonate formations, controlling filtration in an acid fracture, and conversion in matrix acidification.</p>

General description of the invention

In a non-exclusive version, a method is provided for drilling into a highly compressed subterranean formation that requires density

<p dir="rtl">15 Fluid greater than 14 pounds per gallon including an introduction to a wellbore that passes at least partially through the subterranean formation A watery, cement-forming fluid that includes a dispersant. The aqueous cement-forming fluid includes water, at least one viscoelastic surfactant (VES), at least one monovalent or polyvalent salt, at least one magnesium powder comprising 30-80 by weight magnesium oxide (MgO). magnesium oxide (and more</p>

<p dir="rtl">20 20 wt% dolomite, at least one retarder, weighting material</p>

At least one dispersan dispersant. The method also includes increasing the viscosity of the aqueous fluid constituting the cement due to the activity of the elongated micelles forming the at least one viscoelastic surfactant, wherein the at least one monovalent salt is present in an effective amount to perform false cross-linking of the elongated viscoelastic surfactant micelles to further increase the viscosity of the fluid.

<p dir="rtl">25 Watery. Additionally, the method includes forming a cement by the reaction of at least one magnesium powder and water, wherein cement formation is retarded from what would otherwise occur without the presence of the retarder.</p>

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The method also includes inhibiting fluid loss to the formation by the combined activity of cross-linked viscoelastic surfactant micelles and a magnesium oxide-based cement.

Also provided, in a non-exclusive form, is a water-forming fluid cement with a density of more than 14 pounds per gallon (more than 1.7 kg/L) for use in inhibiting the loss of cement-forming fluid.

<p dir="rtl">5 of cement to a subterranean formation, wherein the aqueous fluid includes water, at least one viscoelastic surfactant, at least one monovalent or polyvalent salt, at least one magnesium powder comprising 30-80 wt% magnesium oxide and more than 20 wt% magnesium oxide. Dolomite, at least one retardant, at least one weighing agent, and dispersing material. Optionally, a defoaming agent is included.</p>

<p dir="rtl">10 Brief explanation of the drawings</p>

Figure 1 is an overhead view image of mixing the components of an aqueous cement-forming fluid in a mixing container, and opening a vortex after adding the dispersant, where:

Figure 1a is an image of a magnesium oxide based sealing powder containing an aqueous fluid of viscoelastic surfactant in the mixer without dispersant;

<p dir="rtl">15 Figure 1b is an image of a magnesium oxide based sealing powder containing an aqueous fluid of viscoelastic surfactant in the mixer of Figure 1a during the addition of the dispersant; Figure 1c is an image of a magnesium oxide based sealing powder containing an aqueous fluid of viscoelastic surfactant in the mixer of Figure 1b with a dispersant during mixing showing the opening of a vortex after adding a dispersant;</p>

<p dir="rtl">20 Figure 1d is an image of the last set loss control material seal made from the components mixed in Figures 1a-1d after hardening and removal from a mold; Figure 2 is images of an aqueous fluid containing a viscoelastic surfactant; Figure 2a is an aqueous fluid image of a cross-linked viscoelastic surfactant containing a poured sealing powder showing its relatively thick viscosity;</p>

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Figure 2b is an image of a comparative aqueous fluid of a viscoelastic surfactant with that of Figure 2a containing a non-cross-linked sealant powder being poured and showing its relatively thin viscosity;

Figure 3 is a thickening time graph for a 15 lb per gallon (1.8 kg/L) slurry without an agent.

<p dir="rtl">5 Weight at 150°F (66°C);</p>

Figure 4 is a graph of the compressive strength of a 15 psi (1.8 kg-arm/L) mortar without...

Weight factor at 150°F (66°C);

Figure 5 is a thickening time graph for a 16 psi (1.9 kg/L) slurry with a manganese-based weight agent at 200°F (93°C);

<p dir="rtl">10 Figure 6 is a histogram of the compressive strength of a 16 psi (1.9 kgf/L) mortar with a manganese-based weight factor at 200°F (93°C);</p>

Figure 7 is a graph comparing the viscosity of a fluid by a 5550 HPHT viscometer with and without a viscoelastic surfactant; And

Figure 8 is a picture of a loss control material solid set for a 15 lb per gallon (1.8 kg) slurry.

<p dir="rtl">15 carm/litre) after thickening time test.</p>

Detailed description:

A new formula has been discovered for use as a fluid loss solution. Characterization of the new formulation and its application includes the inclusion of viscoelastic surfactants or similar chemistry that allows the formulation to be pumped out and delays its gelation until it is in the appropriate location in the subterranean formation. Contains formula

<p dir="rtl">20 The aqueous fluid contains at least one viscoelastic surfactant or similar chemistry with one or more soluble monovalent salts or p-arenes and/or one or more polyvalent salts or p-arenes. In a non-exclusive embodiment, the formulas herein include aqueous cement-forming fluids with a density of more than 14 lb/gal, alternatively those with a density of more than 14 lb/gal (1.7 kG/L) to about 20 lb/gal (2.4 kG/L). / Liter(;</p>

<p dir="rtl">25 In another, non-exclusive version, more than 14 pounds per gallon (1.7 kilograms per liter) to about 16</p>

Pounds per gallon (1.9 kilograms per liter).

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To prevent or inhibit lost circulation, it is important to avoid premature gel formation but also for the gel to have sufficient viscosity and resistance. As noted, current commercial displays have insufficient operating power. The method and formulation described here can provide a better operating window, and in particular the formulation has at least two additional advantages – (a) it can be formulated with brine such as seawater (b) it can be cleaned

<p dir="rtl">5 After quests to restore the state of the store before quests. Brine is defined here as including, but not necessarily limited to, seawater, product water, synthetic seawater, formation water, brine, b-arene, etc. and mixtures thereof. It has also been discovered that the use of a viscoelastic surfactant, with or without saline, creates a pumpable viscosity sufficient to hold a powder mixture of active ingredients, in non-exclusive examples of which are magnesium-based powder and borate powder. Also choose a powder based</p>

<p dir="rtl">10 Magnesium is important for the functions of this formula. The formula does not harden prematurely under ambient conditions. The active mixture can be pumped to areas in the reservoir and non-reservoir that are subject to fluid loss. After heating to the wellbore temperature, it hardens as a cementitious plug with sufficient resistance to prevent fluid loss. At the end of the run, if needed, the hardened solid can be dissolved with an acid stream. The slurry can be conditioned to have a density in the range 10 lb. per gallon to 16 lb. per gallon (1.2 to</p>

<p dir="rtl">15 1.9 kg/L) and higher. The plug hardening time is controlled by a boron-based retardant.</p>

for about 1 to about 3 hours and more separately up to a temperature of 70°F (21°C) and up to 230°F (110°C); alternatively cement formation is stimulated by a temperature between about 90°F and (32°C) separately to approximately 100°F (38°C). The limit value is non-exclusive.

<p dir="rtl">20 Different or alarm temperatures range from approximately 90°F (32°C) separately to approximately 100°F (38°C). For each of these temperatures, realize that these are the initial temperatures and that at most Cases of increased temperature.</p>

The method and formulation include two phenomena: a) pseudo-crosslinking of elongated or “worm-shaped” viscoelastic surfactant micelles composed of viscoelastic surfactant molecules

<p dir="rtl">25 Elasticity, which helps the gelatinous fluid fill spaces with its viscous flow and b) harden like a cement plug</p>

(in a loss zone) during the period of time and high temperature. This again is false synaptic connection

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The viscoelastic surfactant forms an elongated worm-shaped micelle structure in the presence of monovalent and/or polyvalent salts such as magnesium chloride, calcium chloride, calcium bromide, potassium chloride, aluminum chloride, and mixtures Thereof, and so on. This is not polymer-based 5-crosslinking and cross-linking. In a non-exclusive theory or explanation, when a fluid containing a viscoelastic surfactant and at least one monovalent or polyvalent salt is heated the at least one monovalent or polyvalent salt binds to, attaches to or bonds to micelles of the viscoelastic surfactant with each other, thereby increasing the viscosity of the fluid further. This is somewhat similar to the way crosslinks of various polymer chains are connected and sometimes called “pseudo-crosslinking”, but it is believed that the way

The monovalent or at least one polyvalent salt of elongated viscoelastic or “worm-shaped” surfactant micelles is entirely distinct from the cross-linking that occurs in polymerases.

In the formulas and methods described herein, magnesium powder also acts as a strongly hardening cement; 15 boron-based compounds act as a retardant to control this hardening/setting process with respect to temperature and time. While

A greater explanation of hardening and retardation chemistry follows.

Viscoelastic surfactants for use herein include, but are not limited to, non-ionic, cationic, amphoteric, and zwitterionic surfactants. Specific examples of surfactants 20 include, but are not limited to, dihydroxyalkylglycinates

dihydroxyl alkyl glycinate, alkyl ampho acetate or propionate, alkyl betaine, alkyl amidopropyl betaine and alkylimino mono- or di-propionates derived from special waxes, fats and oils. Quaternary amine surfactants are typically cationic, and 25 betaines are typically dicharged. The thickening agent can be used in combination with a soluble salt

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Inorganic water or an organic additive such as phthalic acid, salicylic acid or salts thereof.

Some nonionic fluids are inherently less damaging to product formations than cationic acid species, and are more effective per pound than anionic gelling agents. It is for antiseptic substances

5 Amine oxide viscoelastic surfactants are able to offer more gel-forming power per pound, making them less expensive than other fluids of this type.

The same gel-forming agents of amine oxide 0 2(1)+811 can have the following structure (I):

R'

Where R is the alkyl or alkyl amido group ranging from about 8 to 24 10 carbon atoms and? Separately are alkyl groups ranging from about 1 to 6 carbon atoms. in

In one non-exclusive embodiment, R is an alkyl or alkyl amido group ranging from about 8 to 16 carbon atoms and Al' are separately alkyl groups ranging from about 2 to 3 carbon atoms. Viscoelastic surfactants are suitable One specific type is the ARMOVIS EHS® VES surfactant supplied by Akzo Nobel. Its structure has been clarified

15 In formula (II). This viscoelastic surfactant helps create viscosity to a higher temperature of up to 350°F (177°C) in the presence of a monovalent and/or polyvalent salt.

R Ri

-- «. (II)

CR

ARMOVIS EHS compound name: Erucamidopropyl

Hydroxypropylsultaine 20

Typical properties of an ARMOVIS EHS® VES surfactant include: 0 Appearance - Liquid, with 50% solids

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<p dir="rtl">• Pour point - 41°F (12°C)</p>

<p dir="rtl">• pH-8</p>

<p dir="rtl">• Specific gravity- 1.0</p>

<p dir="rtl">• Solvent bottle - ethanol (EtOH)/propylene glycol (PG)/water</p>

<p dir="rtl">5 As mentioned, monovalent and/or polyvalent salts are used as pseudocrosslinking agents, which also increase the crosslinking of elongated micelles and thus increase the viscosity even further. Figure 7 is a graph comparing the viscosity of a fluid by a 5550 HPHT viscometer with and without a viscoelastic surfactant to illustrate that the presence of a viscoelastic surfactant may significantly increase the viscosity up to the time of viscoelastic break. Figure 8 is a picture of the solidification of a solid after a thickening time test</p>

<p dir="rtl">10 15 lb per gallon (1.8 kg/L) slurry.</p>

Another suitable specific viscoelastic surfactant is amine oxide with formula (I), specifically AROMOX® APA TW, supplied by Akzo Nobel, which can be used for the lower temperature range to create insimulated cross-linking up to 250°F (121°C). .

The amount of viscoelastic surfactant relative to water in an aqueous fluid may range from

<p dir="rtl">15 About 0.01 wt% separately to about 10 wt%; About 0.01 gps separately to about 2 gps. As used for a range, “separately” means that any lower limit value can be combined with an upper limit value to produce an appropriate alternative range. Alternatively, the at least one viscoelastic surfactant is present in the aqueous fluid in an amount from about 0.01 gps separately to about 2 gps; Alternatively about 0.05 gps separately</p>

<p dir="rtl">20 to about 1 gps. It may be noted that the abbreviation "gps" also refers to the aqueous cement-forming fluid described here as a basis.</p>

Suitable monovalent salts, divalent salts, or polyvalent salts include, but are not limited to, sodium chloride, potassium chloride, ammonium chloride, sodium bromide, sodium 25 formate, and potassium formate. formate, calcium chloride, calcium bromide, magnesium chloride, chloride

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Zinc chloride, zinc bromide, aluminum chloride, brine, and combinations thereof. For illustration, in some non-exclusive embodiments, simply using brine sufficient monovalent salts or sufficient polyvalent salts are provided for pseudo-crosslinking of elongated viscoelastic surfactant micelles.

<p dir="rtl">5 For appropriate amounts of at least one monovalent or polyvalent salt, the amount of at least one monovalent or polyvalent salt is present in the aqueous fluid in an amount from about 0.01 separately to about 10% by weight of the cement. Magnesium chloride salt in amounts up to 10 wt% of cement have been used successfully depending on the application, but salts can also be used until weight saturation. An alternative range can range from about 1 wt to about Χ10 wt 10 of cement.</p>

Sealant powder or magnesium powder reacts in the presence of water to form magnesium oxysulfate cement according to the formula (ill) as follows:

15

20)

25

16) 03735037 h 82*49?09*82

Magnesium sulfate

Magnesium powder is essentially a mixture of magnesium oxide and dolomite. Dolomite is any non-aqueous carbonate material composed of calcium magnesium carbonate with the chemical formula 2(003)01. In one non-exclusive embodiment the magnesium powder has 30-80! wt. magnesium oxide and more than 20X wt. dolomite. In one non-exclusive embodiment the amount of at least one magnesium powder present in the aqueous fluid comprising the cement or cement is about 100X by weight.

The formation of magnesium oxysulfate cement is controlled by sodium borate retardant. Sodium borate reacts with magnesium oxide and MgS04 to form magnesium borate thereby inhibiting the formation of magnesium oxysulfate. Sealant powder (magnesium) can be used to design 10 psi to 14 psi (1.2 to 1.7 kg/L) fluid as well as higher density fluids; This is used at a ratio of Χ100 by weight of cement. Essentially a water fluid density of 8.342 pounds per gallon (1 kg/L) and sealing powder are used to increase the weight to density.

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Favorite. Magnesium oxide powder is limited to use up to 230°F (110°C). 1d and 8 are images of a solid cement seal produced from magnesium oxysulfate

magnesium oxysulfate

Suitable additives include, but are not limited to, sodium borate, 5-boric acid, disodium tetraborate decahydrate, and combinations thereof. Butt is also sometimes called boron powder. As noted, the delayer is used to delay the hardening time of the aforementioned magnesium powder-based cement. It has been discovered that conventional binders such as lignosulfonate, a synthetic phosphate-based binder for Portland cement, do not work here due to the different hydration and hardening chemistry. Some 10 Suitable proportions of boron-based powder or backside in the fluid range from about 0.01% may be used separately to about 20 wt% of cement and higher; Alternatively, the percentage can range from about 1% separately to about 15% by weight of cement.

The aqueous fluid may also optionally include a defoaming agent where necessary to control excessive foaming that may interfere with the application of the fluid loss material. Suitable defoaming agents include, but are not limited to, silicone-based defoaming agents, such as silicone emulsions, etc. It has been found that alcohol-based defoaming agents do not work with this system. Typical defoaming agent concentration ranges from about 0.001 gps individually to about 0.1 gps (about 1.5 ×10–4 to about 7.6 ×10–3 L/kg).

<p dir="rtl">20 The abbreviation "gps" stands for Gallon per Sack of Cement (in the case of the aqueous cement formulations described here, magnesium powder). One stack of this cement contains 55 lbs (25 kg). All calculations are based on The Turkish rule for additives/ingredients depends on the amount of cement while taking 100% cement in the formula to design cement mortar. The approximate density range for water-fluid cement slurry ranges from about 10 lb25 per gallon to about 16 lb per gallon (1.2 to 1.9 kg/L) and higher, as will be explained below.</p>

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The initial hydrogel begins to build up at about 80°F (27°C); alternatively at about 100°F (38°C) and the system can operate as high as about 300°F (149°C) .

As noted, an advantage of the gel cement system described here is that after the cement sealer is no longer needed

<p dir="rtl">5 Solid, it may be dissolved with an acid stream in a conventional manner. Suitable acids for flow include, but are not necessarily limited to, hydrochloric acid, formic acid, acetic acid, nitric acid, methane sulfonic acid, glutaric acid, glutamic acid, succinic acid. succinic acid, adipic acid, oxalic acid, glycolic acid</p>

<p dir="rtl">10 acid, lactic acid, aminopolycarboxylic acids and mixtures thereof.</p>

In one embodiment, the methods and compositions herein performed in the absence of Polymart form a gel and/or gel or aqueous fluids whose viscosity values are improved by Polymart. There is a known difficulty with polymer art that if it forms a filter paste that penetrates the formation, it is difficult to remove the paste without damaging the area near the

<p dir="rtl">15 The wellbore is permanently in formation. However, the combination use of polyart and polyart dimers can be beneficial. For example, PolyArt can be added to a viscoelastic surfactant fluid to further improve fluid loss control. Polymers that can be used as fluid loss control agents include, but are not limited to, various starches, modified starches, polyvinyl acetates, polylactic acids,</p>

<p dir="rtl">20 Guar and other polysaccharides, hydroxyethylcellulose and other derived celluloses, gelatins, etc.</p>

The aqueous fluids and methods as described herein may be used in combination with other techniques including, but not limited to, US Patents 8,544,565 and 8,921,285.

<p dir="rtl">25 In some circumstances, formation pressure requires heavier, denser silt to balance against this higher pressure. For silt densities greater than about 14 pounds per gallon (1.7 kg/L), additives can be added.</p>

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Weight to silt. Furthermore, particulate weighing materials including barium sulfate, micronized barite, hausmannite, ilmenite, manganese tetroxide, and hematite, as examples of non-exclusive embodiments, are added, and fine dense particles are evacuated to the clay to increase its density. When using weight materials like these in addition

<p dir="rtl">5 Magnesium oxide based fluid cementitious composition of gelatinous viscoelastic surfactants, dispersants, such as sulfonated copolymers, with a molecular weight between about 2,000 and about 200,000, alternatively between about 5,000 and about 20,000 should be added. , used with 0.05 to 0.5 wt% to fluid formula for uniform dispersion of solid weight agents and temporary reduction of fluid viscosity for easier pumping. Weight and dispersing agents do not reduce fluid performance</p>

<p dir="rtl">10 The ultimate control of damage loss. Available dispersants such as lignosulfonate, acetone formaldehyde, and polyacrylamide cannot be used with the magnesium oxide-based cement crosslinking fluid as these dispersants reduce the crosslinking structure of the magnesium oxide cement. A sulfonated copolymer based dispersion can be used in these weighted formulations without affecting the cross-linked magnesium powder based cement.</p>

<p dir="rtl">15 The present invention will be explained in more detail in the following non-exclusive examples which are designed only to further illustrate the invention but do not limit its scope.</p>

Conduct laboratory mixing of the loss control material

The basic loss control material used in combination with weighing materials to create denser silt is the same as that described in pending U.S. patent application No. 14/729,567, filed

<p dir="rtl">20 On June 3, 2015. The fluid loss control material is mixed in a bottom-vane type mixer used in preparing fluid slurries , as follows:</p>

<p dir="rtl">• Fill the required amount of fresh water or salt water and set the speed to 1000 rpm</p>

minute.

<p dir="rtl">• Add monovalent and/or polyvalent salt and stir for 2-5 minutes.</p>

<p dir="rtl">25 • Add the viscoelastic surfactant and mix for 10-15 minutes.</p>

<p dir="rtl">• Add defoaming agent when necessary.</p>

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<p dir="rtl">• Adding sealant powder, weighing agent and dispersing agent at 2000-4000 rpm</p>

minute. Leave the mixture to become uniform.

As shown in Figures 1A-1D (Figure 1), a bird's-eye view of mixing cement-forming aqueous fluid components in a blender container, opening the vortex after adding the dispersant.

<p dir="rtl">5 More specifically, Figure 1a is an image of a magnesium oxide based sealing powder containing an aqueous fluid of viscoelastic surfactant in a mixer without dispersant and without vortex. Figure 1b is an image of a magnesium oxide based sealant powder containing an aqueous fluid of viscoelastic surfactant in the blender of Figure 1a during dispersant addition. Figure 1c is an image of a magnesium oxide based sealing powder containing an aqueous surfactant fluid.</p>

<p dir="rtl">10 Viscoelastic in a mixer Figure 1b with dispersant during mixing shows the opening of the vortex after adding the dispersant. The presence of a vortex indicates mixability and pumpability. Figure 1d is a photograph of the last fluid loss control seal made from the blended components in Figures 1a-1c after hardening and removal from a mold.</p>

Test results

<p dir="rtl">15 Formulas with densities greater than 14 lbs per gallon (1.7 kg/L)</p>

For a required fluid density of more than 14 lb per gallon (1.7 kG/L) separately up to the upper limit of 20 lb per gallon (2.4 kG/L) fluid density, weighing agents are usually added, such as barium sulphate, Micronized barite (>6 microns with about 2 microns average particle size), hausmannite, ilmenite, manganese tetroxide, hematite, calcium carbonate, dolomite, magnetite,

<p dir="rtl">20 And combinations thereof and other fine, dense particles, into the fluid to increase the density. The weight materials may range from about 1% separately to about 150% by weight of the cement, alternatively from about 3% to about 50% by weight of the cement, and in another non-exclusive embodiment from about 5% to about 40%. By weight of cement, as necessary to achieve the preferred density.</p>

In a non-exclusive embodiment, barite, which is acid-insoluble, may be included in the formula

<p dir="rtl">25 by about 10 to about 30 wt% of cement to produce slurries of about 15 to about 16</p>

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pounds per gallon (about 1.8 kg/L to about 1.9 kg/L). However, these magnesium oxide-based cements are soluble in acid.

In one trial, MICROMAX, a manganese tetroxide, was used. It is a reddish-brown mineral powder that is inert in color and is denser than barite with a density of 4.8 garm/cm3 and has an average size.

<p dir="rtl">5 0.5 micron particle. MICROMAX with a magnesium oxide based cement setting system is acid soluble above 90% with 15% hydrochloric acid. Table 1 provides acid solubility test data for MICROMAX at 16 lb per gallon (1.9 kg/L). 2" x 2" (5.1 x 5.1 cm) tube with weight factor</p>

MICROMAX (manganese tetroxide) in 15% HCl, where 93.1% acid solubility was observed. The formula was also tested with magnesium oxide based cement for 12 and 14 lbs per gallon.

<p dir="rtl">(1.4 and 1.7 kilograms per liter).</p>

Table 1

Acid solubility with MICROMAX

<tr><td><p dir="rtl">12.5 lbs per gallon</p><p dir="rtl">2 inch x 2 inch tube</p><p>(5.1x5.1)</p><p dir="rtl">Centimeter(</p></td><td><p dir="rtl">12.5 lbs per gallon</p><p dir="rtl">2 inches x</p><p dir="rtl">2 inch tube</p><p>(5.1x5.1)</p><p dir="rtl">Centimeter(</p></td><td><p dir="rtl">12.5 lbs per gallon</p><p dir="rtl">2 inches x</p><p dir="rtl">2 inch tube</p><p>(5.1x5.1)</p><p dir="rtl">Centimeter(</p></td><td><p dir="rtl">Acid solubility</p></td></tr><tr><td><p>292</p></td><td><p>2155.4</p></td><td><p>144.58</p></td><td><p dir="rtl">Initial weight</p><p dir="rtl">For the pipe (Garm)</p></td></tr><tr><td><p>2000</p></td><td><p>1200</p></td><td><p>800.46</p></td><td><p dir="rtl">Acid</p><p dir="rtl">User (15%)</p><p dir="rtl">HCL((Gram))</p></td></tr>

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<tr><td><p dir="rtl">5 With stirring</p></td><td><p dir="rtl">4 With stirring</p></td><td><p>4</p></td><td><p dir="rtl">Time to thawing (hours)</p></td></tr><tr><td><p>20.1</p></td><td><p>15.0)7</p></td><td><p>4.93</p></td><td><p dir="rtl">Residual matter</p><p dir="rtl">Remaining (grams)</p></td></tr><tr><td><p>Ζ93.1</p></td><td><p>%93</p></td><td><p>%96.6</p></td><td><p dir="rtl">Solubility(%)</p></td></tr>

For a gelatinous magnesium oxide based cement fluid formulation of a viscoelastic surfactant, dispersants, such as sulfonated copolymers, in a non-exclusive example having a molecular weight of 10,000, used in an amount from about 0.05 to about 0.5 by weight, may need to be added to the fluid formulation

<p dir="rtl">5 To help uniformly disperse the solid weight agents and to temporarily reduce the viscosity of the fluid for ease of pumping. Weight and dispersing agents do not reduce the performance of the final fluid for controlling circulation loss. Available dispersants such as lignosulfonate, acetone formaldehyde, polyacrylamide do not work with the false crosslinking fluid with magnesium oxide based cement because these dispersants reduce the entire false crosslinking structure.</p>

10 A suitable non-exclusive sulfonated copolymer dispersion is a copolymer of sulfonic acid and monomers shown in the following structural formula:

<img file="SA8062B1_D0001.tif" />

Where: U = 2-propenoic acid 2-Ρ openoic acid; V = benzene sulfonic acid 4-[(2-methyl-2 propenyl)oxy, salt

15 sodium sodium salt; w = 2-propene-acid! Sulfonic 2-Ρ ropene-l-sulfonic acid, salt

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2 Methyl-, sodium 2 methyl-, sodium salt; x = 2-propenoic acid, 2-methyl-, ester

<p>2. The sulfonated monomer group is characterized by its lack of affinity - propenoic acid, 2-methyl-, methyl ester.</p>

Water, aromatic structure with average molecular weight by weight between about 2,000 to about 200,000; Alternatively from about 5,000 separately to about 15,000 and in

<p dir="rtl">5 One non-exclusive embodiment 10,000. The sulfonated copolymer dispersion is added to the weighed formula in a range from about 0.01% separately to about 2 wt% of the cement; Alternatively from about 0.05% separately to about 0.5% by weight of cement. A particularly relevant, non-exclusive example of a sulfonated copolymer is AQUATREAT AR=540, which is a copolymer of a sulfonic acid and another monomer with an average molecular weight of 10,000.</p>

<p dir="rtl">10 Another convenient low-molecular weight polymeric dispersion is NARALEX D72®, supplied by Akzo Nobel, which is a copolymer with sulfonate and carboxyl groups.</p>

A sulfonated copolymer based dispersion material is suitable for a cross-linked magnesium powder based cement. Table 2 shows formulation examples for 12.5 lb per gallon slurry (1.5 kg/L)

<p dir="rtl">15 Without dispersant and 15 psi per fluid gallon (1.8 kGRM/L) including dispersing agents. Laboratory test data show that a 0.3 wt% sulfonate copolymer may temporarily reduce fluid viscosity within 50% and has a compressive strength greater than 2.07 MPa (300 psi) up to 250°F (121°C) with acid solubility. Table 2</p>

20 12.5 lbs per gallon and 15 lbs per gallon fluid conditioning

<tr><td><p>bwoc and gps</p></td><td><p>bwoc and gps</p></td><td><p dir="rtl">Additive</p></td></tr><tr><td><p dir="rtl">12.5 lbs per gallon</p><p dir="rtl">(1.5 kg/L)</p></td><td><p dir="rtl">15 Pounds per gallon (1.8 kg/L)</p></td><td><p dir="rtl">Fluid density</p></td></tr><tr><td><p>6.23 GPS</p></td><td><p>3.06Gps</p></td><td><p dir="rtl">pure water</p></td></tr><tr><td><p>0.01 GPS</p></td><td><p>0.01Gps</p></td><td><p dir="rtl">Defoaming agent</p></td></tr><tr><td><p>%3Bwoc</p></td><td><p>%3Bwoc</p></td><td><p dir="rtl">Backside</p></td></tr>

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<tr><td><p>%1Bwoc</p></td><td><p>Bwoc%1</p></td><td><p dir="rtl">salt</p></td></tr><tr><td><p>0.25Gps</p></td><td><p>0.06Gps</p></td><td><p>VES</p></td></tr><tr><td><p>100%Bwoc</p></td><td><p>100%Bwoc</p></td><td><p dir="rtl">Sealing powder</p></td></tr><tr><td><p dir="rtl">not required</p></td><td><p>0.3</p></td><td><p dir="rtl">Dispersing material</p></td></tr>

Table 3 presents the performance of various dispersants in a 15 lb per gallon (1.8 kg/L) formula. The table shows that without the dispersant, the fluid containing the cross-linked loss control material cannot be falsely mixed. The table also shows that the cross-linked structure Falsely entangled with a substance

<p dir="rtl">5 Loss control Do not continue with commonly used weighing material dispersants such as lignosulfonate-, acrylamide-, and naphthalene-formaldehyde- or acetone-formaldehyde-based dispersants, while dispersants maintain</p>

Dispersion of sulfonated copolymer on Ze'ev crosslinker.

Table 3

Streamline loss control material - 15 lbs per gallon (1.8 kgm/L) with various dispersants

<tr><td><p dir="rtl">Acrylamide</p></td><td><p dir="rtl">For Gnu</p><p dir="rtl">Sulfonate</p></td><td><p dir="rtl">It is based on acetone formaldehyde</p></td><td><p dir="rtl">Its foundation</p><p dir="rtl">Naphthalene formaldehyde</p></td><td><p dir="rtl">Sulfonated copolymer</p></td><td><p dir="rtl">Al-Qaeda</p></td><td><p>RPM</p></td></tr><tr><td rowspan="6"><p dir="rtl">no</p><p dir="rtl">maybe</p><p dir="rtl">Mix it up</p></td><td><p>25</p></td><td><p>27</p></td><td><p>25</p></td><td><p>40</p></td><td rowspan="8"><p dir="rtl">no</p><p dir="rtl">maybe</p><p dir="rtl">Mix it up</p></td><td><p>3</p></td></tr><tr><td><p>35</p></td><td><p>50</p></td><td><p>35</p></td><td><p>50</p></td><td><p>6</p></td></tr><tr><td><p>110</p></td><td><p>165</p></td><td><p>120</p></td><td><p>175</p></td><td><p>100</p></td></tr><tr><td><p>140</p></td><td><p>160</p></td><td><p>150</p></td><td><p>130</p></td><td><p>200</p></td></tr><tr><td><p>160</p></td><td><p>180</p></td><td><p>170</p></td><td><p>125</p></td><td><p>300</p></td></tr><tr><td><p>255</p></td><td><p>290</p></td><td><p>240</p></td><td><p>155</p></td><td><p>600</p></td></tr><tr><td rowspan="3"></td><td><p>26</p></td><td><p>30</p></td><td><p>27</p></td><td><p>60</p></td><td><p dir="rtl">10 Seconds</p></td></tr><tr><td><p>30</p></td><td><p>30</p></td><td><p>28</p></td><td><p>72</p></td><td><p dir="rtl">1 minute</p></td></tr><tr><td><p>35</p></td><td><p>35</p></td><td><p>30</p></td><td><p>97</p></td><td><p dir="rtl">no</p></td><td><p dir="rtl">10 minute</p></td></tr><tr><td><p dir="rtl">no</p></td><td><p dir="rtl">Yes</p></td><td><p dir="rtl">Yes</p></td><td><p dir="rtl">Yes</p></td><td><p dir="rtl">Yes</p></td><td></td><td><p dir="rtl">note</p><p dir="rtl">Confused</p></td></tr>

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<tr><td><p>-0.3</p><p>0.5</p></td><td><p>0.3</p></td><td><p>0.3</p></td><td><p>0.3</p></td><td><p>0.3</p></td><td></td><td><p dir="rtl">Dispersant concentration (% by weight)</p></td></tr><tr><td><p dir="rtl">no</p></td><td><p dir="rtl">no</p></td><td><p dir="rtl">no</p></td><td><p dir="rtl">no</p></td><td><p dir="rtl">Yes</p></td><td></td><td><p dir="rtl">Continue crosslinking</p></td></tr>

Table 4 shows illustrative formulas for achieving 15 lb/gal (1.8 kG/L) and 16 lb/gal (1.9 kG/L) fluid densities according to the methods and formulations described here.

Table 4

5 Formulas to achieve 15 psi (1.8 kgf/L) and 16 lbf (1.9 kgf/L) fluid densities

<tr><td><p>bwoc and gps</p><p dir="rtl">16 Pounds per gallon</p></td><td><p>bwoc and gps</p><p dir="rtl">15 Pounds per gallon</p></td><td><p dir="rtl">Additive</p></td></tr><tr><td><p>3.6 GPS</p></td><td><p>3.54Gps</p></td><td><p dir="rtl">pure water</p></td></tr><tr><td><p>0.01 GPS</p></td><td><p>0.01Gps</p></td><td><p dir="rtl">Defoaming agent</p></td></tr><tr><td><p>%5Bwoc</p></td><td><p>%10Bwoc</p></td><td><p dir="rtl">Backside</p></td></tr><tr><td><p>%0.5Bwoc</p></td><td><p>Bwoc%0.53</p></td><td><p dir="rtl">salt</p></td></tr><tr><td><p>0.06Gps</p></td><td><p>0.07Gps</p></td><td><p dir="rtl">Stress reliever</p><p dir="rtl">Surfactant</p></td></tr><tr><td><p>100%Bwoc</p></td><td><p>100%Bwoc</p></td><td><p dir="rtl">Sealing powder</p></td></tr><tr><td><p>%30Bwoc</p></td><td><p>%10Bwoc</p></td><td><p dir="rtl">Weight factor</p></td></tr><tr><td><p>%0.5Bwoc</p></td><td><p>%0.5Bwoc</p></td><td><p dir="rtl">Dispersing material</p></td></tr>

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Table 5 and Figures 3-6 show the thickening times and compressive strengths for 15 psi and 16 psi formulations at test temperatures of 125°F (52°C) and 200°F (93°C).

Table 5

5 Thickening times and compressive strength results for 15 lb per gallon (1.8 kgf/L) and 16 lb per gallon (1.9 kgf/L) fluids

<tr><td colspan="2"><p dir="rtl">16 Pounds per gallon</p></td><td colspan="2"><p dir="rtl">15 lbs per gallon</p></td><td><p dir="rtl">Designs</p></td></tr><tr><td><p dir="rtl">200 degree</p><p dir="rtl">Fahrenheit (93°C)</p></td><td><p dir="rtl">125 degree</p><p dir="rtl">Fahrenheit (52°C)</p></td><td><p dir="rtl">200 °F (93°C)</p></td><td><p dir="rtl">125 degree</p><p dir="rtl">Fahrenheit (52).</p><p dir="rtl">Celsius(</p></td><td><p dir="rtl">Temperature degree</p><p dir="rtl">Test, Fahrenheit (°C)</p></td></tr><tr><td><p>03:1</p></td><td><p>0.8:2</p></td><td><p>54:1</p></td><td><p>26:1</p></td><td><p dir="rtl">TT (hour: minute)</p></td></tr><tr><td><p>)11.8(1179</p></td><td><p>)14.8(2153</p></td><td><p>)5.4(784</p></td><td><p>)15.2(220.2</p></td><td><p dir="rtl">UCA Pounds per square inch (MPa)</p></td></tr>

The method and fluid for producing water-based cement are provided as a lost solution. There is an important difference to the use of materials

Only viscoelastic surfactants or similar chemistry that the aqueous fluid here allows the formula to be pumped and hinders gel formation until the fluid is in its proper position in the formation. As noted, the fluid 10 contains a surfactant or similar chemistry with one or more soluble monovalent salt or pyrene and/or one or more polyvalent salt or pyrene. To prevent or inhibit loss of strength, it is important to avoid premature gel formation and for the gel to have adequate viscosity and resistance. Existing commercial displays have insufficient operating power; Examples are commercial loss control technology based on polymer resin sealants, vibrating fluidized slurries or high fluid loss grains.

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Existing hydro methods and fluids provide a better operating window. Other advantages include: (a) it can be formulated with soft water and (b) it can be cleaned after jobs to restore the tank to pre-job condition – that is, with little or no damage to the tank. The use of a surfactant creates Viscoelastic, with or without saline, pumpable viscosity sufficient to hold a powder mixture of active ingredients,

<p dir="rtl">5 Specifically magnesium based powder used for preferred density and Burt's powder used as control delay</p>

In hardening of cement. Various weighing agents, such as barite, micronized barite, hausmanite, hematite, ilmenite, combinations thereof and other dense fine particles can be used with magnesium oxide based powder to increase density. The choice of magnesium-based powder is also important for using this formula. The formula does not accidentally harden under ambient conditions. The active mixture is pumped to areas

<p dir="rtl">10 Potential fluid loss in the reservoir and non-reservoir parts of the underground formation. After exposure to the borehole temperature, it hardens as a cement plug with sufficient resistance to prevent and/or inhibit fluid loss. At the end of the procedure, if necessary, the hardened solid can be dissolved with acid solubility.</p>

In the foregoing specification, the invention is described with reference to particular embodiments thereof, and is described as being effective in providing methods and compositions for applying aqueous gel-like fluids to a surfactant.

<p dir="rtl">15 Viscoelastic containing powders to inhibit or prevent fluid loss. However, it is clear that various modifications and changes can be made to it without deviating from the broader scope of the invention as described in the attached claims. Therefore, the specifications are illustrative and not exhaustive. For example, special combinations of viscoelastic surfactants, berene, monovalent salts, divalent salts, polyvalent salts, magnesium powders, retardants, agents are expected to be</p>

<p dir="rtl">20 Weight, dispersants, optional defoaming agents and other components that are within the variables to be protected, but not specifically identified or tested in a special method or aqueous fluid, are within the scope of the present disclosure. Likewise, methods for preventing and inhibiting fluid loss are expected to be successfully performed using mixing methods, temperature ranges, and ratios somewhat different from those described or illustrated here.</p>

<p dir="rtl">25 The words “including” and “including” as used throughout the Safeguards are interpreted as “including without limitation.”</p>

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The present invention may suitably comprise, consist of, or consist substantially of, the disclosed elements and may be performed in the absence of the undisclosed element. For example, a method of drilling into a subterranean formation may be provided, comprising, substantially consisting of, or consisting of, introducing into a wellbore that passes at least partially through the subterranean formation an aqueous fluid that forms cement of dense

<p dir="rtl">5 More than 14 pounds per gallon (lb per gallon) (1.7 kilograms per litre), wherein the aqueous cement-forming fluid is primarily composed of water, at least one viscoelastic surfactant, or a monovalent or polyvalent salt At least one, at least one magnesium powder, at least 30-80 wt% magnesium oxide and more than 20 wt% dolomite, at least one retardant, at least one weighing agent or material, at least one dispersing material and, optionally, a removal agent;</p>

<p dir="rtl">10 foam. The method also essentially comprises or consists of increasing the viscosity of the cement-forming aqueous fluid due to the activity of elongated micelles forming the at least one viscoelastic surfactant; Wherein the at least one monovalent salt is present in an amount effective to effect cross-linking of the elongated viscoelastic surfactant micelles to further increase the viscosity of the aqueous fluid, forming a cement by the reaction of at least one magnesium powder and water, wherein formation is retarded.</p>

<p dir="rtl">15 cement from what would otherwise occur without the presence of the backside, inhibiting the loss of fluid fluid to the formation by the combined activity of the cross-linked viscoelastic surfactant micelles and the cement.</p>

An aqueous cement-forming fluid with a density of more than 14 pounds per gallon (1.7 kg/L) was also provided for use in inhibiting the loss of the aqueous fluid to a subterranean formation, used to isolate a cement area.

<p dir="rtl">20 The aqueous fluid is composed primarily of water, at least one viscoelastic surfactant, at least one monovalent or polyvalent salt, at least one magnesium powder comprising 30-80 wt% magnesium oxide and more than 20 wt% magnesium oxide. Dolomite, at least one retardant, at least one weighing material or agent, at least one dispersing agent, and optionally a defoaming agent.</p>

<p dir="rtl">25 Bookmark drawings</p>

Figure 3

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A graph of the coating time for 15 pounds per gallon (1.8 kilograms per liter) slurry without a weighing agent at

150 °F (66°C)

B The beginning 5/17/2015 - 11:13:43 AM

Downtime: 5/17/2015 - 2:30:21 PM

<p dir="rtl">5 Initial Bc: 57 Bc</p>

C 30 0:00:00 :Bc

0:06:30:Bc 70

0:07:30:Bc 100

D Temperature (°F)

<p dir="rtl">10 E pressure (kpsig)</p>

and compatibility (Bc)

g Time (hour: minute)

Figure 4

A Graph of compressive strength for 15 psi (1.8 kgf/L) mortar without agent

<p dir="rtl">15 Weight at 150°F (66°C)</p>

B The beginning 5/17/2015 - 3:15:07 pm

Downtime: 5/21/2015 - 8:10:51 AM

24 CS Hour: Type B Compressive Strength (more than 14 lbs/gal)

C 50 psi: 3:15:30

20 500 psi: 5:14:30

Final CS: 1842 psi

D Temperature (°F)

E pressure (kpsig)

and compressive strength (pounds per square inch)

<p dir="rtl">25 h Transmission time (microseconds/inch)</p>

g Time (hour: minute)

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Figure 5

A graph of the coagulation time of 16 pounds per gallon (1.9 kg/liter) slurry without a weighing agent.

Manganese based at 200°F (93°C)

B The beginning 6/22/2015 - 10:50:43 AM

<p dir="rtl">5 Downtime: 6/22/2015 - 12:13:00 PM</p>

Initial Bc: 41 Bc

C 30 0:00:00 :Bc

0:04:30:Bc 70

0:06:30:Bc 100

<p dir="rtl">10 D Temperature (°F)</p>

E pressure (kpsig)

and compatibility (Bc)

g Time (hour: minute)

Figure 6

<p dir="rtl">15 A Histogram of compressive strength for a 16 lb per gallon mortar with a manganese based weight agent.</p>

At 200°F (93°C)

B The beginning 6/23/2015 - 11:14:38 AM

Downtime: 6/24/2015 - 11:15:40 AM

24 CS Hour: Type B Compressive Strength (more than 14 lbs/gal)

20 C 50 psi: 1:19:00

500 PSI: 1:27:00

Final CS: 1179 psi

D Temperature (°F)

E pressure (kpsig)

<p dir="rtl">25 and compressive strength (pounds per square inch)</p>

h Transmission time (microseconds/inch)

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g Time (hour: minute)

Figure 7

a Viscosity resistance of the fluid by a 5550 HPHT viscometer with and without surfactant

Viscoelastic surfactants

<p dir="rtl">5 B Temperature (°F)</p>

C Viscosity (centipoise)

d Time (minutes)

e with a viscoelastic surfactant

And without viscoelastic surfactant

<p dir="rtl">10 g Temperature (°F)</p>

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