Well drilling position selection method in consideration of coal seam crushing degree

Abstract

The invention discloses a well drilling position selection method in consideration of a coal seam crushing degree, and belongs to the field of coalbed methane drilling engineering. A bulk rock core is obtained from a coal seam drilling hole of a block to be drilled to determine rock type coefficients and geology strength indexes of coal rocks; the experimental sample processing is performed for the obtained bulk rock core to obtain multiple sets of standard cylinder coal rock core samples; the uniaxial compressive strength test is performed for the obtained multiple sets of coal rock cores by an uniaxial compressive strength tester, and the average value of multiple sets of test values serves as the uniaxial compressive strength of the coal rocks in the block to be drilled; a coal rock crushing coefficient formula is determined according to the Hoek-Brown criterion for evaluating the coal seam crushing degree; and a ground stress field of the coal seam in the bock to be drilled is determined according to a multiple linear regression method, and the maximal main stress value, the minimal main stress value, the uniaxial compressive strength and the rock body coefficient of each unit of the coal seam of the block to be drilled are substituted into the coal rock crushing coefficient formula to calculate the crushing coefficient of the coal seam of the block to be drilled.

Description

Technical field: [0001] The invention relates to a drilling well position selection method considering the fragmentation degree of a coal seam, and belongs to the field of coal bed methane drilling engineering. Background technique: [0002] At present, the general principles of well location layout for coalbed methane exploration and development: ① Coalbed methane resource evaluation; ② Selection of favorable blocks; ③ Well location layout. In the above steps, the layout of drilling wells mainly depends on the selection of coalbed methane enriched areas and engineering experience. However, according to the data fed back from the coalbed methane drilling site, drilling accidents such as well wall collapse and pipe sticking often occur in the drilling process of the well site optimized by the above method. Therefore, it is urgent to provide a method of drilling well location selection from the perspective of preventing drilling risks. [0003] The anisotropy of physical and...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the defects of the prior art, the object of the present invention is to provide a method for selecting a drilling location considering the degree of coal seam fragmentation, reduce the drilling risk caused by coal seam fragmentation, and assist in solving the problem of well location selection in the field of coalbed methane drilling engineering

Images