SU1620391A1 - Method of operating underground reservoir in permafrost rocks - Google Patents

Abstract

The invention relates to drilling operations under the conditions of the spreading of permafrost. The goal is to increase the efficiency of operation of underground reservoirs (PR) during the disposal of waste drilling mud (P) in them by preventing the PR arch from being warmed up and simultaneous circulating water supply. The control wells are drilled along the PR contour and above the PR in the roof of the latter. At the wellheads, the temperature (T) is determined before the start of injection and the critical T values corresponding to the beginning of the melting of the CR set. Drilling pumps are pumped in griodically. In each period, the injection of P is carried out until the critical wells are reached from the dead wells. They withstand P until it is clarified and the clarified portion is pumped to the surface. The remainder of P is kept until it is completely frozen - reaching T at the bottom of the control wells, equal to the original. After that, the pumping of the drilling P. is resumed. 4 Il. cl

Description

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The invention relates to a technique for conducting drilling operations under the conditions of the distribution of permafrost, and more specifically to problems of environmental protection, water supply, waste disposal and storage of drilling fluids,

The purpose of the invention is to increase the efficiency of operation of underground disposal of waste drilling wastewater in the process of drilling reservoirs while disposing of wastewater in them with the possibility of simultaneous circulating water supply of drilling fluids by preventing the reservoir roof from thawing and simultaneous circulating water supply.

Figure 1 shows the underground reservoir in permafrost, section; 2 shows the design of the injection well; FIG. 3 shows the design of the production well; figure 4 - placement of injection, production and control wells, type in the plan.

In the permafrost 1, two vertical wells are drilled — injection 2 and operational 3, the bottomholes of which are in the interval of continuous ice content 4 and communicated via reservoir 5. The injection well consists of a vertical section; (trunk) 6, section (trunk) 7 of the set of angle and horizontal section (trunk) 8, in which

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respectively, the cooled direction (barrel) 9, thermally insulated tubing (tubing) 10, curved pipe 11, diffuser 12 with center 13 are arranged, the design of the production vertical well 3 is equipped with a cooled direction (barrel) 14, thermally insulated tubing 15 and tubing 16 The contours, t, e, dome 17 and surfaces 18 of reservoir 5 are limited to control wells 19 and 20, on the bottom of which sensors 21 are installed.

The method is carried out as follows.

The site of the underground reservoir is determined by drilling research wells with core sampling to a depth of no more than the bottom of the permafrost. The research results are also used to determine the location of the cluster, and the wells themselves can later be transferred to the production 3, injection 2 or test wells 19. The interval and depth of the reservoir are selected. Preference is given to the intervals of the occurrence of clear ice, icy and high-icy rocks 4, containing the minimum number of oversized and clogging inclusions and creating an isolated space during thawing. The injection well 2, in the presence of subsidence rocks at the mouth, is supplied with a cooled barrel 6, for example, an air convective one. The borehole 2 is surrounded with a column and rotational method using shortened screw engines and a curved sub pipe 11 drills a corner set section 7 and a horizontal section 8 in the azimuth direction of the production well 3. To prevent premature erosion of the shafts 7 and 8 and ensure the design trajectory, drilling is conducted on the cooled solution. After crossing or approaching the horizontal bore 8 and the producing well 3, the tubing with the diffuser 12 is lowered into the injection well, and the thermally insulated tubing 10 is installed in the upper part to prevent the thawing and development of thermokarst in the subsidence zone of the subsidence rocks. the lead pipe and the swivel are connected to the steam line, after which steam is supplied to the tubing and ice is thrown out and a cavity is formed, for which the columns are sequentially moved from 3 x heating wells 2

the formation of an underground tank filled with melt water and condensate.

The production well 3 is equipped with a cooled barrel 14, is cased and cemented, lowered to the maximum depth of the tubing 16 and thermally insulated tubing 15. Water is extracted, for example, using airlift with air injection into the tubing and lifting of the water-air mixture through the tube space. Water is used for circulating water supply to the rig.

To monitor the formation of the reservoir and its size, temperature sensors 21 are lowered into the test wells 19 and 20,

5 for example, based on the water circuit of an electrical circuit with a warning light on the surface. Test wells 19 and 20 are drilled into the dry, without filling with liquid. In the case of liquid in the well caused by thawing and expansion of the boundaries of tank 5 to the sides and upwards, the liquid closes the circuits, and the signal light located in the master room lights up, Consequently, it is necessary to stop the work on the injection of steam or spent drilling mud, fluid, air, and to give an opportunity due to freezing back (due to the occurrence of

0 large volume of rocks with negative temperatures) to reduce the size of the tank. The dimensions of the tank are determined based on the estimated disposal volume of the waste drilling wastewater

5 the entire period of drilling bush.

After pumping fluid from the reservoir to the injection well 2, drilling waste water is pumped, treated with coagulant reagents, such as sulfuric acid acid aluminum, and after the liquid has refluxed and clarified, it is pumped out of the tapping well 3 and used for technical needs.

5 is used for storing drilling mud. ra with its subsequent application.

After the completion of the drilling of the bush, the wastewater and solid residues are refluxed and frozen, and

0, cement bridges are installed in the injection and production wells after extraction of the tubing and thermally insulated tubing 10.

PRI me R. At the Bovanenkovskoye site of the birth of the peninsula: Yamal, near the well cluster, drilling of 400 m deep wells were made at a distance of 50 m from each other. At a depth of 100-120 m, layers with an ice content of 95% were found. Research wells were transferred to injection2 and production3. Equal distances from well 1 and 2 drilled test wells 10 and 20, with the distance between the extreme wells being 50 m and the depth being 120 m.

The depth of the central control well is 95 m, i.e. above the roof of the high ice layer. In the presence of subsidence rocks at the mouth, the injection and production wells were supplied with a cooled direction, for example, with PeRo-li-oil, with air-convection cooling, with HBO-55 / 83-00. During the construction of the reservoir, steam with a temperature of 150 ° C and a pressure of 0.3 MPa was supplied to the drilled wells. These parameters allow maintaining high rates of tank construction. By analogy with the construction of storage tanks for petroleum products, the construction period of the reservoir was 10 days. Due to the fact that according to the proposed method, technological stoppages of the drilling waste removal process (thawing of the surrounding massif) are required, two smaller tanks were constructed, which made it possible not to stop the drilling waste disposal process, but to switch from one reservoir to another. Drilling rigs were fed at a temperature of 6-10 ° C. When temperature sensors were triggered, the injection of drilling wastewater was stopped for about a day, which is enough for HS, drill cuttings, At a time, the second tank produced a backfill. When temperature sensors triggered on this reservoir, drilling wastewater was pumped out to the first reserve / ap, and in the second, drilling sludge was freezing.

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j- 4- t ... y P r tXtC-: 4 :: to vl / l ::: rk:: l v; l. The capacity of these tanks was calculated for the total volume of disposal of drilling cuttings from the drilling of the bush. After the drilling of the bush, these reservoirs were completely filled with drilling wastewater, which after a certain time were frozen together with the surrounding rocks, the reservoirs turned into frozen strata, merging with the surrounding frozen rocks.

Claims (1)

Claim of the method of operation of an underground reservoir in permafrost rocks, including pumping one well into a reservoir of fluid, settling it in the reservoir and pumping it out of the reservoir through other wells, characterized in that, in order to increase the efficiency of exploitation of underground reservoirs during disposal of waste drilling mud in them by preventing thawing of the roof of the reservoir and simultaneous circulating water supply, along the contour of the reservoir and above the reservoir in the roof of the latter, control is drilled The wells, determine the temperature before the start of injection and critical temperatures corresponding to the onset of the reservoir arch, on the holes of the indicated wells, and the injection of brown ostorosis is carried out, heatsily, at 3TON (injection of pscTtopo. i each period is performed up to 7, 5- not at the wellheads, critical tsrrr -ur, after which the solution is extruded to its clarification and the clarified part of it is poured to the surface, and the shuyu part of the solution is endured to its full frost v control Well wells equal to the original, after which the injection of drilling mud is resumed. / 19 21 17 13 shh -./g} $: Јt F fcy / .-. chk: ± l + 1 - .v :: &: $ &#: Ъ: Ы: & FIG. 2 2Q about-- nineteen N5 water + air Air . .vVv. ; -H ---:  H & 18 WITH . S