CN102041987B

CN102041987B - Method for water control and oil production increasing acidification of oil well at water content increasing stage of low-pressure heterogeneous reservoir

Info

Publication number: CN102041987B
Application number: CN200910235761.4A
Authority: CN
Inventors: 黎晓茸; 杨华; 徐永高; 张书平; 赵振峰; 杨承宗; 李永长; 杨立华; 张涛; 马丽萍
Original assignee: China Petroleum and Natural Gas Co Ltd
Current assignee: China Petroleum and Natural Gas Co Ltd
Priority date: 2009-10-13
Filing date: 2009-10-13
Publication date: 2014-01-15
Anticipated expiration: 2029-10-13
Also published as: CN102041987A

Abstract

The invention relates to a method for the water control and oil production increasing acidification of an oil well at the water content increasing stage of a low-pressure heterogeneous reservoir, which comprises the following steps of: washing a shaft by using a flushing fluid, and filling the flushing fluid into a sleeve; replacing the flushing fluid in an oil tube with acidification liquid, and introducing the acidification liquid into the middle part of an oil layer; sealing well a packer seat, sealing an annular space of an oil jacket, replacing the acidification liquid in the oil tube with high-viscosity displacing liquid, introducing the displacing liquid into the oil layer, fastening an oil tube valve and a sleeve valve up, performing reaction for 30min to 8h, and performing pumping and flow back by using an oil tube swab; when an acid flooding pressure is less than or equal to 7MPa, replacing the acidification liquid with the high-viscosity displacing liquid in a volume which is 2/3 of that of the oil tube of the shaft, and performing reaction for 3h; when the acid flooding pressure is more than or equal to 7MPa, replacing the acidification liquid with the high-viscosity displacing liquid in the volume which is 4/5 of that of the oil tube of the shaft, and performing reaction for 3h; and after the pressure is released, opening the mouth of the well, and setting an oil tube pumping drum for pumping and flow back until reaching a water oil ratio, wherein the deepest pumping position is 300 to 500m above a perforated interval of the oil layer. The method avoids the probability of high water yield of the acidified oil well, poor effects achieved by measures or scrap of the oil well.

Description

The oil well water-control oil-increasing acidization tool in low pressure heterogeneous reservoir Water-Content Rise stage

Technical field:

The present invention relates to a kind of acidization tool that is applicable to the oil well water-control oil-increasing of low pressure heterogeneous reservoir.

Background technology:

The oil well of low pressure heterogeneous reservoir, because of Water-Content Rise, causes output significantly to decline; Because reservoir pressure is lower, if adopt conventional acidifying, acidification liquid can be under well liquid column pressure, first crack or the macropore along water outlet flows to, and can enter earth formation deep by seepage flow, even more depths to oil-water interfaces, makes acid solution cannot enter the oil impregnate duct of obstruction, thereby cause that oil well oil increasing effect is very little, aquifer yield rises by a larger margin; In most cases, produce oil not after acidifying, large volume production water, causes oil well almost to be scrapped; If, adopt first water blockoff (stifled temporarily) acidifying again, because oil layer blocking is serious, blocking agent cannot be injected, and pressure raises and causes crack to produce, and acidifying result not only can not increase oil, causes on the contrary producing water and significantly rises.

Summary of the invention:

The object of the invention is with the higher displacement fluid of a certain amount of viscosity (with 0.5% xanthans that is heated to 90 ℃ of dissolvings), part acid solution to be replaced in oil reservoir; Utilize head of liquid in pit shaft that remaining acid solution is pressed into oil reservoir; Utilize for the high viscosity of putting acid solution and replace the characteristic that liquid is not easy to enter oil reservoir, thus the deep degree that restriction acid solution enters oil reservoir.Utilize cup packer to set, seal liquid in oil sets annular space, limit it and enter stratum, avoid it that acid solution is pressed into earth formation deep.

The oil well water-control oil-increasing acidization tool in low pressure heterogeneous reservoir Water-Content Rise stage of the present invention is: first with flushing fluid 1 by the pit shaft wash clean that circulates, and be full of sleeve pipe 2; With acidifying liquid 3 for putting in oil pipe 4 flushing fluid to oil reservoir 5 middle parts; Seated packer 6, is fastened respectively after oil pipe gate 8 and sleeve gate 9 reaction certain hours, with the oil pipe swab suction row of returning with the acidifying solution in high sticky displacement fluid 7 replacement oil pipes in oil reservoir.

According to injection pressure size determine for put liquid number; As pressure≤7MPa, with 2/3 volume displacement fluid of pit shaft oil pipe volume, replace acidifying liquid, react afterwards 3 hours; When acid filling pressure is larger, with 4/5 volume displacement fluid of pit shaft oil pipe volume, replace acidifying liquid, react afterwards 3 hours; After pressure is laid down, open well head, lower oil pipe suction cylinder aspirates the row of returning, and suction degree of depth bosom is to the above 300-500m of oil reservoir perforated interval, until reach oil-water ratio, lower pump completion.

By high viscosity, replace liquid low-pressure, low discharge capacity for putting pretreating liquid, can remove the obstruction of perforation eye and part seepage flow duct stops up, after reducing injection pressure, due to the sticky effect that replaces liquid and packer of height, restriction pretreating liquid enters the deep of infiltration macropore under well liquid column pressure, lure that the main acid of injecting subsequently more enters oil impregnate duct into, control the continuation fingering of acid solution and link up infiltration duct, when water is produced in restriction, remove oil impregnate duct and stop up, can aspirate at short notice the row of returning again; Thereby when controlling Water-Content Rise, recover and raising oil production level.Even the method has avoided causing the large volume production water of oil well after acidifying, the poor possibility that causes oil well to be scrapped of measure effect.

Accompanying drawing explanation:

Fig. 1 shaft column structure and liquid distribution schematic diagram:

Wherein: 1, flushing fluid 2, sleeve pipe 3, acidifying liquid 4, oil pipe 5, oil reservoir 6, packer 7, high sticky displacement fluid 8, oil pipe gate 9, sleeve gate

The specific embodiment

First use flushing fluid (0.5% clay stabilizer+0.3%8608 activating agent) 1 by the pit shaft wash clean that circulates, and be full of sleeve pipe 2; With acidifying liquid (hydrochloric acid 8%-10%, hydrofluoric acid 1%-3%, acetic acid 6-10%, corrosion inhibiter 0.5%-1%, ferrous stability 1%-2%, surfactant 0.3-0.5%) 3 for putting in oil pipe 4 flushing fluid to oil reservoir 5 middle parts; Seated packer 6, replaces acidifying solution in oil pipes in oil reservoir with high sticky displacement fluid (with 0.5% xanthans that is heated to 90 ℃ of dissolvings) 7, fastens respectively oil pipe gate 8 and sleeve gate 9 reacts after certain hours, with oil pipe swab, aspirates the row of returning.

Claims

1. the oil well water-control oil-increasing acidization tool in low pressure heterogeneous reservoir Water-Content Rise stage, is characterized in that:

First with flushing fluid by the pit shaft wash clean that circulates, and be full of sleeve pipe; With acidifying liquid for putting in oil pipe flushing fluid in the middle part of oil reservoir; Packer set is good, seal oil sets annular space, with the acidifying solution in high sticky displacement fluid replacement oil pipe, in oil reservoir, fasten respectively oil pipe gate and sleeve gate reaction 30 minutes-8 hours, with the oil pipe swab suction row of returning;

As acid filling pressure≤7MPa, with the high sticky displacement fluid of 2/3 volume of pit shaft oil pipe volume, replace acidifying liquid, react afterwards 3 hours; When acid filling pressure > 7MPa, with the high sticky displacement fluid of 4/5 volume of pit shaft oil pipe volume, replace acidifying liquid, react afterwards 3 hours; After pressure is laid down, open well head, lower oil pipe suction cylinder aspirates the row of returning, and suction degree of depth bosom is to the above 300-500m of oil reservoir perforated interval, until reach oil-water ratio, lower pump completion;

It is 0.5% clay stabilizer and 0.3%8608 activating agent that described flushing fluid contains by volume percentage composition; It is hydrochloric acid 8%-10% that described acidifying liquid contains by volume percentage composition, hydrofluoric acid 1%-3%, acetic acid 6-10%, corrosion inhibiter 0.5%-1%, ferrous stability 1%-2%, surfactant 0.3-0.5%; The sticky displacement fluid of described height is the liquid of the xanthans that is heated to 90 ℃ of dissolvings that contains volumn concentration 0.5%.