CN-121993038-A - Active prevention and control method for deep water shallow layer flow drilling

CN121993038ACN 121993038 ACN121993038 ACN 121993038ACN-121993038-A

Abstract

The invention discloses an active prevention and control method for deep water shallow layer flow drilling, which belongs to the technical field of petroleum exploitation and aims to solve the problem that a well wall is easy to collapse after a shallow layer flow stratum is drilled, wherein the active prevention and control method for deep water shallow layer flow drilling comprises a first mode or a second mode, the active prevention and control method for deep water shallow layer flow drilling is used by matching a drilling tool, a casing pipe, a well cementation cement slurry system and the like, the casing pipe and a drill bit enter the shallow layer flow stratum at the same time, the safety and the efficiency of drilling the shallow layer flow stratum can be effectively improved, a shallow layer flow section is effectively sealed, the stability of the well wall is improved, and disasters caused by high shallow layer flow pressure are actively prevented and controlled. Thereby realizing safe and efficient drilling of shallow water flow stratum in the drilling process.

Inventors

WANG GANG
Bahadar, Baltabek
YE YUGUANG
LI XIAOGANG
LIU YUHAN
JI FEI
LI WANJUN
ZHANG CHUNLEI
LIU JITONG
YE YU
ZHONG ZHAO

Assignees

中国石油天然气集团有限公司
中国石油集团工程技术研究院有限公司
中国石油国际勘探开发有限公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (10)

1. An active prevention and control method for deep water shallow layer flow drilling is characterized by comprising a first mode or a second mode; The first mode sequentially comprises the following steps: step 1a, drilling in a borehole (1) using a first drilling tool assembly; step 2a, when encountering a shallow stratum (9), cleaning a wellhead; Step 3a, combining a second drilling tool assembly, and lowering the second drilling tool assembly into the well bore (1), wherein the second drilling tool assembly comprises a casing (10), a drill bit (6), a drill rod (5) and a drill collar (3) which are sequentially connected are arranged in the casing (10), or the second drilling tool assembly comprises the casing (10), and the drill bit (6) is connected to the lower end of the casing (10); Step 4a, the second drilling tool assembly drills into a shallow flow stratum (9); step 5a, after the second drilling tool assembly drills through the shallow stratum (9) to the shallow stratum (9), well cementation operation is carried out; the second mode sequentially comprises the following steps: Step 1b, combining a third drilling tool assembly, wherein the third drilling tool assembly comprises a casing (10), a drill bit (6), a drill rod (5) and a drill collar (3) which are sequentially connected are arranged in the casing (10), the casing (10) is an expansion casing, and the drill bit (6) comprises a hydraulic reamer (7); step 2b, drilling the third drilling assembly in the borehole (1); step 3b, after the second drilling tool assembly drills through the shallow stratum (9) to the shallow stratum (9), the drill bit (6), the drill rod (5) and the drill collar (3) are lifted out; Step 4b, enabling the outer diameter of the sleeve (10) to be enlarged and attached to the well wall; And 5b, performing well cementation operation.
2. The active prevention and control method of deep water shallow layer drilling according to claim 1, wherein in step 1a, the first drilling tool assembly comprises a drill BIT (6), a drill rod (5) and a drill collar (3) which are connected in sequence, the drill BIT (6) is 16"pdc-BIT, and the drill rod (5) is 5" dc.
3. The method of active prevention and control of deep water shallow layer drilling according to claim 1, wherein in step 2a, a double screw is used to clean the wellhead.
4. Active prevention and control method for deep water shallow layer drilling according to claim 1, characterized in that in step 3a, when the permeability of the shallow layer (9) is 10-1000 md and the porosity is 20-40%, the second drilling assembly contains a casing (10), the lower end of the casing (10) is connected with a drill bit (6).
5. The active prevention and control method of deep water shallow layer drilling according to claim 1, wherein in step 5a and step 5b, the bypass valve (8) at the lower end of the casing (10) is opened by means of throwing a ball before performing the cementing operation.
6. Active prevention and control method for deep water shallow layer drilling according to claim 1, characterized in that in step 5a and step 5b, in performing the cementing operation, the cementing slurry is filled in the annular space between the casing (10) and the well wall.
7. The active prevention and control method of deep water shallow flow drilling according to claim 6, wherein the fluid loss of the well cementing cement slurry is lower than 100cm 3 /h, free water is not contained in the well cementing cement slurry, and the critical gel time of the well cementing cement slurry is lower than 30min.
8. The active prevention and control method for deep water shallow layer flow drilling according to claim 6, wherein the well cementation cement paste is light foam cement paste, the thickening time of the well cementation cement paste under the condition of 18 ℃ is 3-5 h, and the compression strength of the well cementation cement paste after 24h under the condition of 7-13 ℃ is more than 4 MPa.
9. The active prevention and control method of deep water shallow layer drilling according to claim 1, characterized in that when the second drilling assembly comprises a casing (10), the casing (10) comprises a drill bit (6), a drill rod (5) and a drill collar (3) which are connected in sequence, the first mode further comprises the following steps: and 6a, releasing the drill rod at the upper part of the upper casing (10).
10. The active prevention and control method of deep water shallow layer drilling according to claim 9, wherein the step 6a comprises the steps of: Step 6.1a, cleaning the inside of the sleeve; Step 6.2a, disassembling the blowout preventer; step 6.3a, lifting out the drill rod; Step 6.4a, checking the drill rod; step 6.5a, cleaning and maintaining the drill rod; step 6.6a, storing or preparing for next use; Step 6.7a, preparing a wellhead.

Description

Active prevention and control method for deep water shallow layer flow drilling Technical Field The invention relates to the technical field of petroleum exploitation, in particular to an active prevention and control method for deep water shallow flow drilling. Background Shallow flow is easily generated in geological environments where sand is loose and unconsolidated, has large porosity and permeability, is covered by low-permeability mud or shale, has a certain inclination in production, has a certain volume in scale, and is sufficient to generate a large amount of sand flow, and is frequently generated in a drilling process. Open-loop drilling with seawater may lead to complex disasters due to higher shallow flow pressures after drilling shallow flow formations. In deep water drilling, a blowout preventer stack is installed on the sea floor, once overflow occurs, timely discovery and treatment are very critical, shallow flows can cause stratum fracture, damage to submarine equipment, such as fracture of a marine riser and the blowout preventer falling into the sea floor, huge economic loss and environmental pollution, the shallow flows can cause interruption of drilling operation, extra repair and control measures are needed, operation time and cost are increased, the existence of high-pressure shallow gas can seriously influence drilling safety, and in theory, gas ejection rate can reach hundreds of thousands of cubic meters per hour, and serious blowout accidents can be caused. Disclosure of Invention The invention provides an active prevention and control method for deep water shallow layer flow drilling, which can effectively improve the safety and efficiency of drilling shallow layer flow stratum, effectively isolate shallow layer flow sections, improve the stability of the well wall and actively prevent and control disasters caused by higher shallow layer flow pressure through the cooperation of drilling tools, sleeves, well cementation cement slurry systems and the like. Thereby realizing safe and efficient drilling of shallow water flow stratum in the drilling process. The technical scheme adopted for solving the technical problems is as follows: an active prevention and control method for deep water shallow layer flow drilling comprises a first mode or a second mode; The first mode sequentially comprises the following steps: Step 1a, drilling in a borehole by adopting a first drilling tool assembly; Step 2a, when a shallow laminar stratum is encountered, cleaning a wellhead; Step 3a, a second drilling tool assembly is combined, the second drilling tool assembly is put into a well bore, the second drilling tool assembly comprises a casing pipe, a drill bit, a drill rod and a drill collar which are sequentially connected are arranged in the casing pipe, or the second drilling tool assembly comprises a casing pipe, and the lower end of the casing pipe is connected with the drill bit; Step 4a, drilling the second drilling tool assembly into the shallow stratum; step 5a, after the second drilling tool assembly drills through the shallow flow stratum, well cementation operation is carried out; The second mode sequentially comprises the following steps: Step 1b, combining a third drilling tool assembly, wherein the third drilling tool assembly comprises a casing, a drill bit, a drill rod and a drill collar which are sequentially connected are arranged in the casing, the casing is an expansion casing, and the drill bit comprises a hydraulic reamer; step 2b, drilling the third drilling assembly in the borehole; step 3b, after the second drilling tool assembly drills through the shallow stratum, the drill bit, the drill rod and the drill collar are started; step 4b, enabling the outer diameter of the sleeve to be enlarged and attaching the sleeve to the well wall; And 5b, performing well cementation operation. The beneficial effects of the invention are as follows: 1. The conventional combined drilling tool is adopted, and can be flexibly applied to different stratum sections. For example, 16"PDC-BIT is used for high efficiency cutting, 8" DC is used for power transmission, and drilling efficiency is improved. Other auxiliary devices are used for specific operations such as vibration and shock. This increases the versatility of the drilling assembly to accommodate different drilling requirements. In addition, the drilling tool assembly has good well wall control capability and adaptability. 2. The adopted well cementation cement slurry has the advantages that the system density is reduced due to the existence of foam, the well cementation cement slurry is beneficial to reducing the well pressure, the well cementation cement slurry is kept stable at different temperatures by adjusting the rheological property, the compression strength after 24 hours reaches more than 4MPa, and the well cementation quality can be ensured. The cement slurry system can efficiently well fix, and plays an important role in ac