The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Feb. 01, 2022

Filed:

Mar. 10, 2020
Applicant:

Southwest Petroleum University, Chengdu, CN;

Inventors:

Qian Li, Chengdu, CN;

Xiaolin Zhang, Chengdu, CN;

Hu Yin, Chengdu, CN;

Wenfeng Yin, Chengdu, CN;

Jiajia Gao, Chengdu, CN;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
E21B 21/10 (2006.01); E21B 21/08 (2006.01); E21B 43/12 (2006.01); E21B 41/00 (2006.01);
U.S. Cl.
CPC ...
E21B 21/106 (2013.01); E21B 21/08 (2013.01); E21B 43/121 (2013.01); E21B 41/0021 (2013.01); E21B 41/0099 (2020.05);
Abstract

A safety drilling system for preventing collapse of water-sensitive formation in the upper part of a high-pressure saltwater layer, which includes a wellhead equipment, a downhole drilling tool, a first injection pipeline, a second injection pipeline, a first return pipeline and a second return pipeline. Upon encountering a high-pressure saltwater layer while drilling, the system injects heavy mud into the annulus of a wellhead through the first injection pipeline to form a heavy mud cap, such that a fluid column pressure in the annulus balances the pressure of the high-pressure saltwater layer. In this case, a fluid column pressure in a drill string is lower than the pressure of the high-pressure saltwater layer.


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