UA17878U - Method for insulation of absorbing layer with abnormally low stratal pressure - Google Patents

Abstract

Method for insulation of absorbing layer with abnormally low stratal pressure includes pumping-in to the well with static liquid level placed lower than the mouth of the well of plugging agent and pressing liquid. Experimentally one determines minimal pressure P1, at which liquid being in the well is pressed to the bed, and maximal pressure P2, at which the plugging agent chosen does not go to the bed. After that one pumps in to the well portions of plugging agent and pressing liquid forming hydrostatic pressure P determined by formula. One pumps in to the well one portion of plugging agent only, with column height hm., and at P1>P2 one pumps in to the well in sequence calculated column heights of plugging agent needed for insulation of absorbing bed in given well interval, at that calculation and pump-in of each next portion of column height is performed after repetitive determination of P1 and P2.

Description

Description of the invention

The proposed useful model relates to the oil and gas industry, namely, to technology 2 of isolating absorbent layers in wells.

The closest in terms of technical essence and the result achieved to the claimed method is a method of isolating an absorbing layer in a well with a static fluid level located below the wellhead, which includes feeding into the well, to a certain depth, a portion of the tamping agent, which is then are pushed into the M.O. reservoir location interval. Ashrafyan, The technology of separation of layers in complicated conditions, -M:, 70 Nedra, 1989, p.183-184).

A known method of injecting a plugging agent into a well involves lowering pipes to a certain depth and creating fluid circulation through pipe and annular spaces. At the same time, the depth of the pipe descent is determined from the condition that when a portion of the plugging agent is located in the pipe and annular spaces above the pipe shoe, the hydrostatic pressure of the columns of portions of the plugging agent and the liquid located above it at the time of filling 19 wells to the mouth will be greater than the formation pressure, and after moving in the interval of the location of the layer will become equal to the layer. Injecting and squeezing the tamping agent, which has a greater density than the liquid in the well, leads to an excess of hydrostatic pressure above the reservoir and, accordingly, to the absorption of the liquid by the reservoir. During the pressing of the tamping agent from the pipe space into the annulus, part of the volume of the tamping agent moves in the direction of the reservoir location. After the compression is completed, the hydrostatic pressure becomes greater than the estimated height of the tamping agent column, which has moved in the direction of the formation, and causes the absorption of the tamping agent, as a result of which the formation remains uninsulated.

In the case of isolation of an absorbing reservoir with an abnormally low reservoir pressure, a known method involves the implementation of absorption liquidation works.

The useful model is based on the task of creating a method of isolating an absorbing reservoir with an abnormally low reservoir pressure, in which a change in the execution of technological operations and the calculation of process parameters makes it possible to isolate an absorbing reservoir with an abnormally low reservoir pressure by moving a portion of the tamping agent to the isolation interval under the influence of of hydrostatic pressure created by columns of portions of tamping agent and anti-squeezing fluid or only by a column of portions of tamponing agent, which in turn ensures reliable isolation of the formation in a given interval without carrying out work on liquidation - absorptions.

The task is solved by the fact that in the method of isolating an absorbing layer with an abnormally low formation pressure, which includes injection into a well with a static level of liquid placed below the wellhead, a tamping agent and a compressing fluid, the minimum pressure is experimentally determined

Zo P, at which the liquid in the well is pressed into the formation, and the maximum pressure Po, at which the selected tamping agent is not pressed into the formation, portions of the tamping agent and compressing fluid are pumped into the well, which create a hydrostatic pressure P, which determined by the ratios:

R2R»RI1 | "

VOIV Jon In vny t0 sen dno In dne shi 8 shi 57 ERVEUEneyah . th "» where R. is the minimum pressure at which the liquid in the well is squeezed into the formation, MPa;

P" is the maximum pressure at which the tamping agent is not squeezed into the formation, MPa;

P - hydrostatic pressure of columns of portions of the tamponing agent and anti-squeezing liquid, MPa; - pta. - column height of a portion of the tamping agent, necessary for isolating the absorbing layer in the specified interval of the well, m; their Pta 7 Density of tamponant agent, g/cm; (ee) Mp r. - the height of the column of a portion of anti-squeezing liquid, m; - 2 Rpr. 7 Density of anti-squeezing liquid, g/cm; 0.01 is the transfer coefficient, and, moreover, when creating a portion of the plugging agent necessary for the isolation of the formation in the given interval of the hydrostatic pressure well

Vrede Mei Pevoretne, only one portion of the tamping agent is pumped into the well with a height of

FO Be tph column pla, and at Р"»Ро, estimated portions of tamping agent are successively pumped into the well, which create hydrostatic pressure, the height of which column is determined by the formulas: раРИ»рИ, сешЯ vo EN Nya der! - hydrostatic pressure of the portion column of the tamping agent required for the isolation of the formation in the specified interval of the well, MPa, the height of the pillar of the calculated portion of the tamping agent, m, until the sum of the portions of the tamponing agent reaches the height of 65 columns of the tamping agent necessary for the isolation of the absorbing layer in the given interval of the well,

at the same time, the calculation and injection of each subsequent portion by the height of the pillar incl. performed after repeated determination of R. and R."

The significant distinguishing features of the claimed method are that: 9 - before injecting the tamponant agent and compression fluid into the well, the minimum pressure P. at which the liquid in the well is squeezed into the formation and the maximum pressure Po at which the selected tamping agent is not pressed into the formation; - portions of tamping agent and compression fluid are pumped into the well, which create hydrostatic pressure P, which is determined by the ratios:

Air Force VID non VN - the same

Bk, pcs. St. and ER TV

Binya - when creating a portion of the tamping agent necessary for the isolation of the formation in the given interval of the hydrostatic pressure of the de Mey echo well, only one is injected into the well

I zhd m NE I a portion of the tamping agent with the height of the column NPla, and at Р/'»Ро, calculated portions of the tamping agent are sequentially pumped into the well, which create hydrostatic pressure, the height of which column is determined by the formulas: se Eva

B vm kis

Where am I! - the hydrostatic pressure of the column of the tamping agent portion necessary for the isolation of the formation in the specified interval of the well, MPa, - the vertical height of the column of the calculated portion of the tamponing agent, m, until the sum of the portions of the vertical column is reached. the height and column of the tamping agent, necessary for the isolation of the absorbing layer in the specified interval of the well, while the calculation and injection of each subsequent portion by the height of the column incl. performed after repeated (2,0) and determination of R. and Ro. - - injection of the tamping agent is carried out directly into the mouth of the well, or through pipes, which, when a portion of the tamponing agent is injected, is lowered to the depth of VtvNer-Ner. and when injecting the tamponant agent and anti-squeezing liquid - to the depth M of the door Tshk "Vrm pad cht pi Fe vzhreeh tp - b b i i her b i ri i i ; - de Noor, - depth of descent of pipes when injecting a portion of buffer liquid and tamping agent into the well, m;

Mo: the depth of descent of pipes when injecting portions of buffer liquid, tamponing agent and scouring liquid into the well, m; "

Ner. - depth of static liquid level, m;

Ne p. - the height of the column of a portion of the buffer liquid, which prevents the mixing of the tamping agent with the liquid that is - c in the well, m. a The method is carried out as follows. ,» Before the start of isolation works, the depth of the static level of the liquid, the minimum pressure Ru, at which the liquid in the well is squeezed into the formation and the pressure Ro, at which the tamping agent is not squeezed into the formation, for example by injecting into the formation - polymer compositions with rheological properties identical to the tamping agent. They determine the hydrostatic pressure that will be created by a portion of the tamping agent necessary to isolate the formation in the given interval of the Mei Echo well. If the well is directly in the mouth or in the pipes, because the sachets of Tk VE are lowered to the depth of the Nar-Ne r-Nbvoro, a portion of the buffer liquid (for example, a 1.596-th aqueous solution - KMC) and a portion of the tamping agent with a volume of two mechs are injected: ah and The size of the wells is the diameter of the well in the interval of the reservoir to be isolated.

The buffer liquid has a density and rheological properties close to the density and rheological properties of the liquid present in the well, which provide the possibility of squeezing it into the formation under hydrostatic pressure, with equal P...

Portions of the buffer liquid and tamping agent create a hydrostatic pressure greater than Ru on the liquid in the well, as a result of which the liquid is squeezed into the formation, and portions of the buffer liquid and tamponing agent move down. At the moment of displacement of a portion of the tamping agent in the specified interval of the well, the hydrostatic 60 pressure of the column of the portion becomes equal to P" and its movement stops. In the future, the tamping agent hardens and reliably isolates the layer.

At R'»Ro, into the well directly into the mouth or into the pipes lowered to a depth of N tr. A portion of the buffer liquid and a portion of the tamping agent are SEQUENTIALLY injected, the height of the column and the volume of which are determined by the ratios: b 00OB mEsya

I'm not

When I left the VH, I paid several fees. ch llya i der' - hydrostatic pressure of the column of the portion of the tamponing agent, necessary for the isolation of the formation in the given interval of the well, MPa, and the height of the column of the estimated portion of the tamponing agent, m.

At the same time, a portion of the tamping agent is moved into the formation interval due to the 70. hydrostatic pressure created by the column of the tamping agent, which is greater than P. and equal to P". After waiting for the solidification of the tamping agent, the depth of the static level of the liquid in the well is re-determined Н ср» Р and Р» and at Р'»Р» the next portion of the tamping agent is pumped into the well by the calculated height of the column of water. The operations are repeated until the required interval of the wellbore is filled with portions. and

If a portion of the tamponing agent is the height of a pillar and pa. creates a hydrostatic pressure Р, which corresponds to the ratio Ро»Р»Р. and into the wellhead or into the pipe lowered to a depth that injects portions of the buffer liquid, the tamping agent necessary for the isolation of the formation and the compression fluid, the height of the column of which is determined by the formula:

But ee So EY

Wo EN Ann, you ore cht de Nr. - the height of the column of the anti-jamming liquid portion, m;

Rpr. 7 Density of anti-squeezing liquid, g/cm3.

At the same time, a portion of the plugging agent moves into the formation interval due to the hydrostatic pressure created by portions of the plugging agent and anti-squeezing fluid - sv EK

MU Cho sha which is greater R. and smaller R."

The depth of descent of the Nur pipes prevents the displacement of the buffer liquid into the annular space at a higher productivity of the pumps during the injection of the tamping agent than the intensity of liquid compression into the formation. The depth of descent of the pipes also ensures the delivery of a portion of the tamponing agent to the buffer liquid and prevents it from

TJ displacement of the tamponant agent into the annulus space by the squeezing liquid. (uh)

Examples of the method. m

Example 1

The well, 500 m deep to the mouth, is lined with a production column with a diameter of 14 mm (inner diameter is 12 mm). To isolate the absorbing layer with a formation pressure of 1.62 mMPa located in the interval of 420-500 m, it is necessary to install a cement bridge in the interval of 400-500 m. In the well, there is a reservoir fluid with a density of p-1.08 g/cm З, the depth of the static level H sr-Z5O0m. For the installation of a cement bridge as a tamponing agent, it is envisaged to use a cement mortar made of PCT cement 1-50 with an ore density of 1.82g/cm3 and 0.2m3 of a buffer liquid from a 1.596 aqueous solution of KMC with a density of 1.02g/cm3. c Before installing the cement bridge, determine the pressure Po at which the liquid in the well :c" is forced into the reservoir. For this, 1.25mM of mineralized water with a density of p-1.08g/cm3 is pumped directly into the mouth (which is 100m of column in an operational column with a diameter of 14bmm). With a float and a winch with a periodicity of 1 Ohv. measure the liquid level until it stabilizes. Measurement data - recorded in a log. The level stabilized at a depth of З5О0m. It is assumed that liquid compression into the formation occurs at a depth of З45 m or a minimum hydrostatic pressure of Р 4-0.01.(500-345).1.08-1.67MPa. ш- Determine the pressure Po at which the tamping agent will not squeeze into the reservoir. As an emitting liquid

Ho) rheological properties of the tamponant agent use a 0.890 aqueous solution of PAA. Do they pump a 1.0m well in - 2? (volume of the well in the reservoir location interval M-0.785.0.1262 (500-420)-1.Ω 3)

O.890 aqueous solution of PAA p-1.0Zg/cm Z and 1.0m3 of mineralized water p-1.08g/cmZ (create a hydrostatic pressure of P-0.01. (80.1,034-80.1,08) -1.67 MPa) and periodically measure the level until it stabilizes. The level stabilized at a depth of 340 m. They pump another 0.5m of mineralized water p-1.08g/cm? and measure the liquid level. The level stabilized at a depth of З10m. It is assumed that the squeezing of the 0.895% PAA aqueous solution into the 29th layer takes place at P.2-0.01.(70.1.03--120.1.08)-2.01 MPa. An aqueous solution of PAA is pushed into the formation by injecting mineralized water into the well and taking measurements until a static level is established at a depth of 350 m. Determine the hydrostatic pressure R. which will be created by a portion of tamponing agent and pla when located in the interval of 400-500m. P-0.01.1.82.100-1.82 MPa, 1.67-1.82-2.01. These ratios indicate that a portion of tamping agent with a column height of Pp la-100m ensures the compression of mineralized water and buffer liquid (which has a lower dynamic shear stress than cement mortar) into the formation until it is located in the interval of 400-500m. Determine the volume of tamping agent M and. -0.785.0.1262.100.1.05-1.3m 3, where 1.05 is a coefficient that takes into account the loss of the tamponing agent during preparation and injection into the well. Determine the height of the column of the portion of the buffer liquid: Pe r.-0.2/0.785.0.1262-16m. Determine the depth of 65 pipe descent No. Nor Pv r. 350-16-334 m. Pump-compressor pipes are lowered into the well to a depth of 334 m. Using the tamponage technique, 0.2 m3 of a 1.595% aqueous solution of KMC is injected into the tubing and

1.3m? tamping agent (cement solution) with a density of 1.82 g/cm3. The mineralized water in the well, together with the buffer liquid, create a hydrostatic pressure of P--0.01-(11.08.(500-350)4-41.02.16)-1.78MPa, which is more than 1.67MPa , therefore mineralized water will begin to be squeezed into the formation. In the future, the hydrostatic pressure will increase due to the column portion of the plugging agent, and the latter, squeezing mineralized water and buffer liquid into the layer, will move to an interval of 400-500 m. At the moment of reaching the given depth, the hydrostatic pressure

Rupa.-0.01.100.1.82-1.82 MPa, less than 2.01, so the movement of the tamponant agent stops. After the tamping agent reaches the specified depth, the well is left at rest to wait for the tamping agent to harden. In the future, the depth of the location of the "head" of the cement bridge is determined by lowering the pipeline 70 times.

Example 2

The 500m-deep well is lined up to the mouth with a production column with a diameter of 14 mm (inner diameter 12 mm). In order to isolate the formation with a formation pressure P of -1.08MPa located in the interval of 420-500m, it is necessary to install a cement bridge in the interval of 400-500m. The density of the liquid in the well is yr-1, O8g/cm U. 12 The depth of the static level Nor-400m. For the installation of a cement bridge, a cement solution with a density of Pta of 1.84 g/cm 3 and 0.2 m3 of a buffer liquid from a 1.596 aqueous solution is used as a tamping agent

KMC The density of the buffer liquid rbr.-1.02 g/cm 3. Before installing the cement bridge, according to the analogy given in example 1, determine the pressures R. and Ro gR.--1.12MPa, R.-1.35MPa. Determine the pressure P", which will be created by a portion of tamping agent, necessary for the isolation of layer P 7-0.01 Pta"Yt.a.70,01.1,84(500-400)-1,84MPa. 1.8451.35 (Ро2Р"). Determine the height of the column of the tamponing agent portion, which will create hydrostatic pressure corresponding to the ratio Ро-Р'»Р, ВЕД. ра, 35/001 vas. Determine the volume of tamponing agent Mta-0.785.0 ,1262.73.1.05-0.96m 3. Determine the height of the column of the portion of the buffer liquid 29 Re r.-0.2/0.785.0.126 2-16m. Determine the descent depth of the tubing pipes No. No r.v r -400-16 -384m. The tubing is lowered to a depth of 384m. Using the tamponage technique, 0.2m3 of a 1.596% water solution of KMC and 0.92m3 of cement mortar are injected into the tubing. The mineralized water in the well, together with the buffer liquid, will create a hydrostatic pressure of P- 0.01.(100.1.08--16.1.02)-1.14MPa, which is more than 1.12MPa, so mineralized water will begin to squeeze into the reservoir. tamping agent in the interval 427-500 m. P-0.01.73.1.84-1.35 MPa, which is equal to P", - its movement stops. After hardening of the cement mortar, determine the depth of the location of the "head" of the cement bridge H, m -427m.

Before building a cement bridge, by analogy given in example 1, determine P 4 and Po: -

Ri-1.17MPa, R.-1.37MPa. Determine the hydrostatic pressure of the required column portion of the tamponing agent

P'-0.01.1.84.30-0.55MPa, which is less than 1.17MPa. Determine the height of the column of a portion of pressing fluid from mineralized water with a density of р-1.08 g/cm U, E.g. -1.37-0.55/0.01.1.08-76 m. Determine the hydrostatic pressure of the column of the portion of tamponant agent and anti-squeezing fluid P-O0.01.(1.84.30--1.08.76)-1.37 MPa, 1.17-1.37. "

They take the height of the anti-shaking fluid column /-Нпр-7Ω. P-0.01.(1.84.304-1.08.70)-1.308 MPa, Z n 70 A1l7«1.308«1.37. Determine the volume of a portion of tamponing agent shu! мат ч ЖИ - Э хз Determine the volume of a portion of the pressing liquid. With the help of tamponage pumps of the equipment, 0.2 m of Z 1.596 aqueous solution of KMC, 0.4 m3 of tamponing agent (cement solution) with a density of p-1.84 g/cm Z and 0.87 m3 of mineralized water with a density of p are pumped into the wellhead. -1.08g/cm Z, Close the mouth and leave the well to wait for the solidification of the plugging agent. - Thus, the application of the method of isolation of an absorbing layer with abnormally low formation pressure allows to achieve a technical result, namely the possibility of isolating an absorbing layer with (ee) abnormally low formation pressure due to the movement of portions of the tamping agent into the isolation interval -1 50 under the action of hydrostatic pressure , created by a portion of the tamponing agent and anti-squeezing fluid or only a portion of the tamponing agent, which in turn ensures reliable isolation of the formation in the specified interval without i42) carrying out work on liquidation of absorptions.

Claims (1)

The formula of the invention is a method of isolating an absorbing formation with an abnormally low formation pressure, which includes injecting into a well with a static level of liquid placed below the wellhead, a tamping agent and a pressing fluid, which is characterized by the fact that the minimum pressure P is experimentally determined at which the liquid , which is in the well, is pressed into the formation, and the maximum pressure P 5, at which the selected tamping agent is not pressed into the formation, portions of the tamping agent and squeezing fluid are injected into the well, which create hydrostatic pressure P, which is determined by the ratios: sons 2 menanoi VAV Donny 65 what what widowed I - ny Krdov porn vot Janv ay I ee tah Gaya I shivilaryu bnya PEV nya de R. - the minimum pressure at which the liquid in the well is squeezed into the formation, MPa; P" is the maximum pressure at which the tamping agent is not squeezed into the formation, MPa; P - hydrostatic pressure of columns of portions of the tamponing agent and anti-squeezing liquid, MPa; Npta - column height of a portion of the tamping agent, necessary for isolation of the absorption layer in the specified interval of the well, m; 70. Yes - density of tamping agent, g/cm; born - the height of the column of the anti-jamming liquid portion, m; with. pr. 7 Density of anti-shaking liquid, g/cm; 0.01 - the transfer coefficient, and when creating a portion of the tamping agent necessary for the isolation of the formation in the specified interval of the well hydrostatic pressure t RotP' P; and re ih de Mei Pevoretne , KK KhNEU Ina peaks, in this case, only one portion of the tamping agent is injected into the well with the height of the column pla, and at P'»Po, calculated portions of the tamping agent are sequentially injected into the well, which create hydrostatic pressure, the height of the column is determined by by the formulas: Ро»Р"»Ру, Пя не и пкт ЛИ дер! - hydrostatic pressure of the column of the portion of the plugging agent necessary for the isolation of the formation in the specified interval of the well, MPa; - and the height of the column of the calculated portion of the plugging agent, m, and until the sum is reached portions, including the height of the column of the tamping agent, necessary for the isolation of the absorbing layer in the given interval of the well, while the calculation and injection of each subsequent portion by the height of the column of water is performed after re-determination of R. and Ro. "and co. Official Bulletin "Industrial Property ". Book 1 "Inventions, useful models, topographies of integrated circuits", 2006, M 10, 15.10.2006. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. - and? - -and (ee) -and IR e) 60 b5