Method for thermal action application to highly-viscous oil deposit

The invention relates to the development of oil fields, in particular to methods for thermal effects on reservoir containing a highly viscous oil.

There is a method of development of the oil reservoir (RF patent number 2,199,004 on 19.01.2001, the, E 21 B 43/24), according to which the exercise tunneling excavation below the oil reservoir and drilled from it pologovosstayuschie injection and production wells and then pumped into the steam injection wells, and oil is taken from the wells.

The disadvantage of this method is to combine the development of mining in one injection and production wells. This leads to a limitation of the pressure and the rate of steam injection into injection wells at risk of it breaking in mines, where oil production is carried out. The consequence of the limited rates of steam injection is to reduce the rate of oil production.

The closest to the technical nature taken as a prototype, is a method of heat exposure on heavy oil reservoir (RF patent number 1,512,210 on 08/25/87, the, E 21 B 43/24), including a selection of oil through the mining and pologonaklonnye horizontal wells drilled from mining excavation, at the bottom of the reservoir, steam injection into the reservoir through injection wells, drilled from the injection of excavation at the top of the reservoir, dividing the thickness of the reservoir into tiers, each of which has consistently performed steam injection while before steam injection to the appropriate tier of lower fluid dynamic level below that tier.

Disadvantage of this method is to reduce the oil recovery due to the weak involvement in the thermal influence its lower part, as injection wells are drilled from the mines located in the upper part of the reservoir inclined downward, and pairs, tending to spread upwards, accumulates in the upper part of the reservoir, not enough warming up the lower portion, with a large number of injection wells, dividing the oil reservoir into tiers, significantly increase the cost of drilling.

Furthermore, drilling and injection wells towards each other does not preclude their intersection or location in the zone of interference, which leads to rapid steam breakthroughs in production wells, increased heat loss and as a result, to reduce oil withdrawal.

The object of the present invention is to increase the oil recovery by enhancing warm the bottom of the reservoir and prevent heat loss due to the break in steam production wells.

This object is achieved by the fact that the thermal effect on the accumulation of high viscosity oil Selection of oil lead through pologovosstayuschie production wells drilled from the mining excavation, below or at the base of the oil reservoir and the injection of steam into the formation is carried out through injection wells, drilled from the injection excavation .

The essential characterizing features of the claimed invention are:

- Constructing an injection underground workings at the bottom of the reservoir;

- Injection wells drilled pologovosstayuschimi;

- A higher trunk injection wells production wells;

- Carry out periodic steam injection and injection wells were taken from the oil during the termination of the injection of steam into them;

- Stop steam injection into the injection well at the temperature reached in production wells, near the temperature of steam injection, and after lowering the temperature to a temperature of the formation prior to steam injection cycle, the selection of the oil is stopped from injectors and injection is carried out in them steam;

- Injection and extraction mine workings fill plugging composition, such as clay, then verify that the steam injection and oil gathering systems;

- After filling mining plugging composition lead to the development of the deposit surface.

This set of essential features can significantly increase oil recovery by engaging in a more active development of the lower half of the reservoir, to reduce heat loss and increase the rate of steam injection and oil withdrawal because the injection wells located in the lower part of the formation of the production wells over the entire length, then have injection and production wells are drilled on a trajectory close to parallel that prevents crossing over the area of ​​the reservoir wells. This arrangement of injection and production wells using steam tendency to spread up to the roof of the reservoir, provides a constant uniform heating of the reservoir from the bottom up, preventing breakthroughs in steam production wells, while the oil flows into the production wells are also located at the bottom of the reservoir. Periodic injection of steam into the formation and selection of oil from the injection wells during the termination of the injection they couple also enhances oil recovery and filling the oil and mining mining plugging composition after verify that steam injection and oil gathering systems and management of the development of deposits on the surface can increase the rate of pumping steam and oil withdrawal, which also contributes to enhanced oil recovery.

The claimed features of the invention are obvious to one of ordinary skill in our area. In this regard, we believe that the claimed invention involves an inventive step. Declared a set of essential features are not known to us from the prior art, so the claimed invention is novel. The invention is industrially applicable, as the existing domestic equipment and technology developed by us allow the use of the method in its entirety.

1 shows a portion of the deposit developed in the context of the radial arrangement of injection and production wells.

2 shows the same area in the plan.

Figure 3 shows a portion of the deposit developed in the context of a parallel arrangement of injection and production wells.

Figure 4 shows the same portion in plan view.

5 shows a piping arrangement surface from underground steam supplying hole injection well.

Figure 6 shows a diagram of the binding surface mining to underground wells producing wells.

Figure 7 shows a diagram of the binding surface mining to underground wells producing well with large sand from the wells.

For carrying out the process (see para. 1-4) are inclined mine workings 1 through the oil reservoir 2. The oil reservoir 2 (or in the base layer) constructing a mining gallery 3 (square or circular). Above mining picture 3 on the bottom of the reservoir 2 construct injection gallery 4, wherein constructing one picture over the other. From mining galleries 3 of the oil reservoir production wells are drilled pologovosstayuschie 5. From the injection gallery 4 injection wells drilled pologovosstayuschie 6, placing them above the mining. At the same injection and production wells are drilled on a trajectory close to parallel, ie rock faces 6 injection and production wells are located in 5 different horizontal planes and wells 5 and 6 along the entire length do not overlap with each other.

If the radial location of injection and production wells in the area of ​​formation and injection gallery is located above the mining gallery have a common central axis.

In a parallel arrangement of injection and production wells, in addition to the above options, possible embodiment, when the injection gallery, settling over the mining gallery, shifted to one side, that is, the gallery does not have a common axis.

Since the ground surface to the injection gallery steam supplying hole 4 drilled 7, wherein constructing a sump 8 for collecting sand and connect it to the injectors 6. On the surface of the earth steam supplying hole 7 connected to a steam generator 9 (see Fig. 1, 3 and 5).

In a mining gallery 3 also from the ground drilled production well 10 through which oil is pumped to the surface by a pump 11 (see FIG. 6) disposed in the sump 12, which drains oil from 5 wells drilled in tight.

For large sand from the wells using the circuit shown in Figure 7. In this case, the collection and primary preparation of oil is carried out in the development of mining 3. Underground 5 production wells connected to the oil gathering collector 13, on which the produced fluid flows in a sealed oil recovery vessel 14, where it is separated from the sand flows into the sump 12, and then pumped to the surface for deep well pump 11 10, also placed in the sump 12.

After full rehabilitation of the site deposit are steam injection into injection wells 6 9 from the steam generator through steam supplying hole 7. At the same time from all the wells 5 seed oil and is pumped to the surface pumps 11 to 10. In this case, the well is tested for leaks and performance of steam injection and oil gathering systems. At the same time study the interaction between the injection and production wells on cracks. In the case of a couple of breakthroughs in any producing wells are installed injection wells that are the source of a breakthrough, and to work to isolate cracks plugging solutions.

When the temperature reached 5 producing wells close to the temperature of steam injection, stop the steam injection wells at 6, continuing the selection of all oil producing wells Injection wells 5. 7 equipped submersible pumps, which are lowered into the sump 8 is connected to the wellhead 6 oil skimmer collector 13 and are from all injection wells selected oil. After lowering the temperature to the temperature of the reservoir prior to steam injection cycle, stop the selection of oil from the injection wells, remove deep-well pumps and re-injection is carried out in a couple of them.

After checking the integrity and efficiency of steam injection and oil gathering systems, injection and extraction mine workings fill plugging solution, such as clay, and isolated mine workings jumpers, such as concrete. Further development of deposits of lead from the surface.

Steam injection and oil production leads to cost-effective limit.

Example. The inventive method can be implemented on Yarega field heavy oil. Productive reservoir lies at a depth of about 200 m and contains oil viscosity of about 15 thousand μPa · · with the layer thickness of about 20 m. The primary mining method development on the natural formation mode was opened system of mine workings (shafts, drifts, etc. ), passed above the oil reservoir. To implement the method in a Yaregskoye field existing roadways are inclined workings 1 3-5 m below the oil reservoir (1). Under the oil reservoir construct a mining gallery 3. Above mining gallery at the bottom of the reservoir constructing injection 4. From mining gallery Gallery 3 uniformly in the oil reservoir drilled 40 wells pologovoskhodyaschih up to 300 m. In a mining gallery 3 from the surface drilled production well 10, through which oil is pumped to the surface by a pump 11 disposed in the sump 12. 5 wells drilled in tight, connected with a production well 10 into the sump 12 which drains oil. Production wells 5 active sand control is connected to the oil gathering collector 13 (see para. 7), which lay to the oil gathering capacity of 14, which is going to sand, and the oil flows into the sump 12, where all produced oil is pumped by a sucker rod pumps 11 to the surface . The mouth of the production well 10 on the surface of an oil pipeline connecting the oil reservoir, which collects and preparation of oil.

4 from the injection gallery 40 pologovoskhodyaschih drilled wells 300 m long, placing them at 5-7 m above the wells substantially parallel to the production wells, that is wells 5, 6 over the entire length does not intersect with each other.

On the surface of the earth steam supplying drilled hole 7, which is connected to underground injection wells 6 (5). The mouth of the steam supplying wells connected to the steam generator steam pipe 9.

After the arrangement portion in the first stage of development are steam injection into the injection hole 6 (Figure 1) at a pressure of 1.0 MPa at a temperature up to 150 ° C. At the same time check the integrity and efficiency of the entire steam distribution system and, if necessary, repair any faults. Of all the wells 5 are selected oil by controlling its temperature for each well. In the case of steam breakthrough in any production well for her conduct repair and insulation works by injecting into the well a special gel-forming composition (liquid glass, polyacrylamide, etc.).

When the temperature in the producing wells, for example, up to 120-130 ° C (temperature of the steam injection - 150 ° C) to stop the steam injection wells 6, continuing the selection of all oil producing wells 5. 7 steam injection wells equipped submersible pumps, in the run-flat sump 8, 7 is connected to the wellhead and the pipeline are selected from oil injectors 6.

After reducing the temperature of the formation, for example to 70-80 ° C prior to steam injection cycle, the selection is stopped from oil injectors 6 are recovered subsurface pump and re-injection is carried out in them steam.

After checking the integrity and efficiency of steam injection and oil gathering systems, injection and extraction mine workings fill plugging solution, such as clay, and isolated mine workings jumpers, such as concrete. Further development led to the surface of the reservoir by injecting steam into the injection hole 6 and selecting the oil from production wells 5, wherein the steam injection is performed periodically, taking oil from the injection wells during termination of the injection of steam in them. Steam injection and oil production leads to cost-effective limit.