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CN-122014195-A - Well completion fracturing method for multi-branch well

CN122014195ACN 122014195 ACN122014195 ACN 122014195ACN-122014195-A

Abstract

The embodiment of the application provides a multi-branch well completion fracturing method, which comprises the steps of sequentially carrying out completion fracturing operation on each branch well, putting a flexible screen pipe comprising a first flexible pipe column and a second flexible pipe column into the multi-branch well so that the first flexible pipe column stretches into the branch well and the second flexible pipe column is arranged along the main well, putting a flexible fracturing pipe column into the branch well through the flexible screen pipe, fracturing the branch well through the flexible fracturing pipe column, taking out the flexible fracturing pipe column, separating the first flexible pipe column from the second flexible pipe column and taking out the second flexible pipe column from the main well. According to the multi-branch well completion fracturing method, when the flexible fracturing string is used for carrying out fracturing operation, the first flexible string of the flexible screen pipe can provide support for corresponding branch well bores, and collapse of the branch well bores can be avoided relative to open hole fracturing.

Inventors

  • HUANG ZHONGWEI
  • Xie Zixiao
  • WU XIAOGUANG
  • PENG YUHUI
  • LI GENSHENG
  • SHI HUAIZHONG
  • TIAN SHOUCENG
  • SONG XIANZHI
  • WANG HAIZHU
  • Sheng mao

Assignees

  • 中国石油大学(北京)

Dates

Publication Date
20260512
Application Date
20260214

Claims (10)

  1. 1. A multi-branch well completion fracturing method is characterized in that the multi-branch well (10) comprises a main well (11) and a plurality of branch wellbores (12), and comprises the following steps of S100, sequentially performing completion fracturing operation on each branch wellbore (12); a method of performing a completion fracturing operation on individual of the lateral wellbores (12) includes: S101, a flexible screen pipe (100) comprising a first flexible pipe string (110) and a second flexible pipe string (120) is lowered into the multi-branch well (10), so that the first flexible pipe string (110) stretches into a branch well bore (12), and the second flexible pipe string (120) is arranged along a main well (11); S102, a flexible fracturing string (200) is lowered into the branch well bore (12) through the flexible screen pipe (100); s103, fracturing the branch well bore (12) through the flexible fracturing string (200); s104, taking out the flexible fracturing string (200); S105, separating the first flexible pipe string (110) from the second flexible pipe string (120), and taking out the second flexible pipe string (120) from the main well (11).
  2. 2. The multi-lateral well completion fracturing method according to claim 1, comprising performing a completion fracturing operation of said lateral well bore (12) located at a high position prior to said lateral well bore (12) located at a low position.
  3. 3. The multi-branch well completion fracturing method of claim 1, wherein said flexible screen (100) comprises a plurality of pipe units (130), with two adjacent pipe units (130) hinged.
  4. 4. A multi-branch well completion fracturing method according to any of claims 1-3, wherein said first flexible string (110) and said second flexible string (120) are detachably connected by a release tool (140).
  5. 5. The multi-branch well completion fracturing method according to claim 1, wherein said branch wellbore (12) has a deflecting section (12 a) for communicating with said main well (11), said deflecting section (12 a) having a radius of curvature of not more than 8m.
  6. 6. The multi-branch well completion fracturing method of claim 1, wherein said method of performing completion fracturing operations on individual ones of said branch wellbores (12) further comprises: after the running of the flexible screen (100) comprising a first flexible string (110) and a second flexible string (120) into the multilateral well (10), the second flexible string (120) is suspended from the main well (11).
  7. 7. The multi-branch well completion fracturing method of claim 6, wherein the first flexible tubing string (110) comprises a first centralizer (113); After the running of a flexible screen (100) comprising a first flexible string (110) and a second flexible string (120) into the multilateral well (10), the first flexible string (110) is supported to the lateral wellbore (12) by the first centralizer (113).
  8. 8. The multi-branch well completion fracturing method of claim 1 or 6, further comprising: -while running a flexible screen (100) comprising a first flexible pipe string (110) and a second flexible pipe string (120) into the multilateral well (10), running a hanger (20) into the multilateral well (10) with the flexible screen (100) and securing the upper end of the second flexible pipe string (120) in the multilateral well (10) by means of the hanger (20); -the flexible fracturing string (200) is adapted to pass through the pilot hole (21) of the hanger (20) while the flexible fracturing string (200) is run into the branch wellbore (12) via the flexible screen (100); The hanger (20) is removed together as the second flexible pipe string (120) is removed from the main well (11).
  9. 9. The multi-lateral well completion fracturing method of claim 1, further comprising setting said main well (11) and said flexible fracturing string (200) after running a flexible fracturing string (200) into said lateral wellbore (12) via said main well (11) and said flexible screen (100).
  10. 10. The multi-branch well completion fracturing method of claim 1, further comprising, after completion fracturing operations on each of said branch wellbores (12): closing the main well (11) to ensure that the fracturing fluid is sufficiently lost and the propping agent is caused to settle; And opening the main well (11), performing open flow flowback, and discharging residual fracturing fluid in each branch well hole (12).

Description

Well completion fracturing method for multi-branch well Technical Field The application relates to the technical field of petroleum and natural gas drilling, in particular to a well completion fracturing method for a multi-branch well. Background In complex reservoir development, particularly in high steep formations, fault block reservoirs or low permeability reservoirs where space is limited, multilateral well technology is widely used to increase reservoir contact area and single well productivity. The multilateral well extends the branch wellbore through the main well in multiple directions to penetrate the multi-layer or heterogeneous reservoir. It is understood that a multilateral well includes a main well and a plurality of branch wellbores. In the related art, in order to smoothly lower a flexible fracturing string into a branch wellbore, the branch wellbore is subjected to fracturing operation when the branch wellbore is in an open hole state. However, in the related art, the fracturing effect on the branch wellbore is limited and collapse of the branch wellbore is easily caused. Disclosure of Invention The embodiment of the application provides a multi-branch well completion fracturing method which is convenient for smoothly putting a flexible fracturing string into a branch well, and solves the problems that the fracturing effect of a branch well is limited and collapse of the branch well is easy to cause. The multi-branch well completion fracturing method comprises the steps of sequentially carrying out completion fracturing operation on each branch well, setting a flexible screen pipe comprising a first flexible pipe column and a second flexible pipe column in the multi-branch well so that the first flexible pipe column stretches into the branch well to enable the second flexible pipe column to be arranged along the main well, setting a flexible fracturing pipe column into the branch well through the flexible screen pipe, fracturing the branch well through the flexible fracturing pipe column, taking out the flexible fracturing pipe column, separating the first flexible pipe column from the second flexible pipe column and taking out the second flexible pipe column from the main well. In some embodiments, the multi-lateral well completion fracturing method includes performing a completion fracturing operation on the lateral wellbore located at an elevation prior to the lateral wellbore located at a depression. In some embodiments, the flexible screen comprises a plurality of pipe units, with articulation between two adjacent pipe units. In some embodiments, the first and second flexible tubing strings are detachably connected by a release tool. In some embodiments, the branch wellbore has a deflecting section for communicating with the main well, the deflecting section having a radius of curvature of no greater than 8m. In some embodiments, the method of performing a completion fracturing operation for a single lateral wellbore further comprises setting a second flexible string in the main well after the running of a flexible screen comprising the first flexible string and the second flexible string into the multilateral well. In some embodiments, the first flexible tubing string includes a first centralizer, and the first flexible tubing string is supported in the lateral wellbore by the first centralizer after the running of a flexible screen including the first flexible tubing string and a second flexible tubing string into the multilateral well. In some embodiments, the method further comprises running a hanger with the flexible screen into the multilateral well while running a flexible screen comprising a first flexible string and a second flexible string into the multilateral well, and securing an upper end of the second flexible string in the multilateral well by the hanger, the flexible fracturing string adapted to pass through a pilot hole of the hanger while running a flexible fracturing string into the multilateral well via the flexible screen, and removing the hanger together while removing the second flexible string from the main well. In some embodiments, the multi-lateral well completion fracturing method further comprises setting the main well and the flexible fracturing string after running the flexible fracturing string into the lateral well via the main well and the flexible screen. In some embodiments, the multi-branch well completion fracturing method further comprises the steps of closing the main well to enable the fracturing fluid to be sufficiently lost and enable proppants to be settled after completion fracturing operation is carried out on each branch well, opening the main well to implement open flow flowback, and discharging residual fracturing fluid in each branch well. According to the multi-branch well completion fracturing method, the flexible sieve tube comprising the first flexible tubular column and the second flexible tubular column is placed in the multi-bra