CN104141480A

CN104141480A - Slug sand-adding process for fracturing

Info

Publication number: CN104141480A
Application number: CN201310523172.2A
Authority: CN
Inventors: 银本才; 杨保军; 赵正龙; 万龙; 孙宝才; 刘信党; 唐世东; 庞清鹏
Original assignee: Down-Hole Job That Requires Special Skills Co Of Central Plains Petroleum Works Co Ltd Of China Petrochemical Industry; China Petrochemical Corp
Current assignee: Down-Hole Job That Requires Special Skills Co Of Central Plains Petroleum Works Co Ltd Of China Petrochemical Industry; China Petrochemical Corp
Priority date: 2013-10-29
Filing date: 2013-10-29
Publication date: 2014-11-12
Anticipated expiration: 2033-10-29
Also published as: CN104141480B

Abstract

The invention relates to a slug sand-adding process for fracturing and belongs to the technical field of fracturing engineering for petroleum exploration and development. According to the process, the sand ratio is increased in the later period of a sand-adding phase of each slug sand-adding cycle of shale gas fracturing construction to form a high-sand-ratio phase, and the sand ratio in the phase is identical with that of the next sand-adding cycle. Through observation of the pressure change after the high-sand-ratio phase enters a stratum, subsequent construction is guided, and a fracturing construction task is finished.

Description

A kind of pressure break slug adds sand process

Technical field:

The present invention relates to a kind of pressure break slug and add sand process, belong to petroleum exploration and development fracturing engineering technical field.

Background technology:

Add in sand construction in petroleum exploration and development shale gas pressure break, usually adopt slug formula to add sand technique, be i.e., after the certain prepad fluid of pumping, add the sand stage and an insulating liquid stage of closelying follow is that a slug adds the sand cycle by one, multicycle, alternately to constructing the later stage, starts to add continuously sand to construction and finishes.Each cycle sand is than keeping a fixed value, a rear more last cycle sand of cycle is than high, this sand mode that adds is because a rear cycle sand is than improving suddenly, after easily causing the sand in this cycle to enter stratum, cause that construction pump pressure raises extremely, cause to add sand and stop in advance, or cause construction sand plug to cause constructing unsuccessfully.

Summary of the invention:

The object of the invention is to solve pressure anomaly in shale gas slug sand fracturing process raises, cause adding sand construction premature termination or failed defect, provide a kind of and slow down the pressure break slug that Fracturing Pressure abnormal ascending, raising pressure break add sand coincidence rate and add sand process.

The technical scheme of this process is as follows:

The present invention includes following steps:

1, pump into prepad fluid according to design;

2, pump into first slug and add the sand cycle.Start to add sand according to design sand ratio, within this cycle, add the front 80-90% of sand stage liquid measure, sand is than keeping a definite value, in the time adding sand liquid measure later stage 10-20%, carry high sand ratio, the sand ratio after raising is identical with the sand ratio in the second slug cycle of design, add after sand liquid measure when pumping into the period 1, stop sand, pump into the first slug by design and add the isolation liquid measure in the sand cycle, complete the first slug and add the construction of sand cycle.

3, pump into second slug and add the sand cycle.Start to add sand according to design sand ratio, within this cycle, add the front 80-90% of sand stage liquid measure, sand is than keeping a definite value, in the time adding surplus 20-10% of sand liquid measure later stage, carry high sand ratio, the sand ratio after raising is identical with the sand ratio in the 3rd slug cycle of design, add second round after sand liquid measure when pumping into, stop sand, pump into the second slug by design and add the isolation liquid measure in the sand cycle, complete the second slug and add the construction of sand cycle.

4, repeat above-mentioned 2,3 and pump into program, complete successively the follow-up each section of slug of this well and add the sand cycle.

5, complete and pump into each slug and add sand week after date, according to designing requirement, complete and add continuously sand pump and enter program, and replaced whole pressing crack construction task.

The present invention adds and adds the sand stage in the sand cycle at each slug of shale gas pressing crack construction, adding sand later stage increasing sand proportion, form a high sand ratio stage, this stage sand than the sand that adds the sand cycle with the next one than identical, enter pressure changing behind stratum by observing this high sand ratio stage, if pressure is without obvious fluctuation, pressing crack construction can normally carry out; The fluctuation if pressure obviously rises, can judge that current stratum is unfavorable for that follow-up high sand ratio adds sand construction, there is sand plug risk, but because this high sand ratio stage liquid measure increasing is few, the time is short, in the time causing pressure oscillation, in pit shaft, insulating liquid completes replacement substantially, can not cause and adds sand construction premature termination or construct unsuccessfully.

Detailed description of the invention:

Below in conjunction with embodiment, the present invention is further described in detail.

It is as follows that certain a bite shale gas well pressure break adds sand program:

In above-mentioned adding in sand program, each slug adds the sand cycle and adds the last 10-20% of sand stage liquid measure, increase a high sand ratio stage, this stage sand than the sand that adds the sand cycle with the next one than identical, enter pressure changing behind stratum by observing this high sand ratio stage, if pressure is without obvious fluctuation, pressing crack construction can normally carry out; The fluctuation if pressure obviously rises, can judge that current stratum is unfavorable for that follow-up high sand ratio adds sand construction, has sand plug risk, can reduce the sand ratio in follow-up each cycle, has continued construction.

Claims

1. pressure break slug adds a sand process, it is characterized in that, adds the later stage in sand cycle at each slug, increases a high sand ratio stage, this stage sand than the sand that adds the sand cycle with next slug than identical.

2. a kind of pressure break slug according to claim 1 adds sand process, it is characterized in that, comprises the following steps:

(1) pump into prepad fluid according to design;

(2) pump into first slug and add the sand cycle.Start to add sand according to design sand ratio, within this cycle, add the front 80-90% of sand stage liquid measure, sand is than keeping a definite value, in the time adding surplus 20-10% of sand liquid measure later stage, carry high sand ratio, the sand ratio after raising is identical with the sand ratio in the second slug cycle of design, add after sand liquid measure when pumping into the period 1, stop sand, pump into the first slug by design and add the isolation liquid measure in the sand cycle, complete the first slug and add the construction of sand cycle;

(3) pump into second slug and add the sand cycle.Start to add sand according to design sand ratio, within this cycle, add the front 80-90% of sand stage liquid measure, sand is than keeping a definite value, in the time adding surplus 20-10% of sand liquid measure later stage, carry high sand ratio, the sand ratio after raising is identical with the sand ratio in the 3rd slug cycle of design, add second round after sand liquid measure when pumping into, stop sand, pump into the second slug by design and add the isolation liquid measure in the sand cycle, complete the second slug and add the construction of sand cycle;

(4) repeat above-mentioned (2), (3) pump into program, complete successively the follow-up each section of slug of this well and add the sand cycle;

(5) complete and pump into each slug and add sand week after date, according to designing requirement, complete and add continuously sand pump and enter program, and replaced whole pressing crack construction task.