Borehole stability build sections of horizontal wells for anisotropic coal seam

2014 ◽  
pp. 237-240 ◽  
Keyword(s):  
Coal Seam ◽  
Horizontal Wells ◽  
Borehole Stability

Study on Drilling and Completion Techniques of Horizontal well for Coalbed Methane

2014 ◽  
Vol 513-517 ◽  
pp. 2586-2589 ◽  
Author(s):  
Xin Feng Du ◽  
Yong Zhe Zhao
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Mining Area ◽  
Variable Density ◽  
Technical Problems ◽  
Development Direction ◽  
Drilling Technology ◽  
The Many

Due to the unique reservoir characteristics of the coalbed methane (CBM) in China, many technical problems have to be studied and solved in the development of horizontal wells for CBM. In this paper, based on the V-type wells, we have summarized the many techniques involved in Drilling and completion of horizontal well for CBM in Binchang mining area, such as leakage protection and sealing, geosteering while drilling, remote connection, variable density cementing, Coal seam cavitation, fiberglass casing running into the well, and etc. It is pointed out that the air foam under-balance drilling will be the development direction for coalbed methane drilling technology.

scholarly journals Swelling Pressure of Double-Expansive Material and Its Active Support Effect for Coal Seam Gas Drainage Borehole

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Zhiming Wang ◽  
Yuning Sun
Keyword(s):  
Coal Seam ◽  
Field Tests ◽  
Swelling Pressure ◽  
Support Effect ◽  
Coal Seam Gas ◽  
Borehole Stability ◽  
Gas Drainage ◽  
Nonlinear Fitting ◽  
Improved Stability ◽  
Drainage Borehole

To improve coal seam gas drainage performance, we developed a double-expansive (DE) material to seal the borehole. The swelling process of this material includes an initial swelling stage and a secondary swelling stage. We studied the swelling pressure properties of the DE material under four constraint conditions using a self-made swelling test device. Further, the active support effect of the DE material on the borehole was analyzed by simulating borehole stability with COMSOL Multiphysics software. The results exhibit the following: (1) The swelling pressure of the DE material exhibits time-dependent behavior, and the mathematical relationship between the swelling pressure and time can be obtained by nonlinear fitting. (2) The radial swelling potential is principally formed during the secondary swelling stage, providing the main active support on the radial constraint. (3) The active support imposed on the hole wall can prevent the extension of plastic and damage regions around the borehole, for improved stability of the gas drainage borehole. Finally, field tests demonstrate improved gas drainage performance of the borehole sealed by the DE material compared to a conventional sealing material.

Borehole stability study of coal seam based on orthotropic coal cleats model

2010 ◽  
pp. 457-462
Author(s):  
Wang Baohui ◽  
Yan Xiangzhen ◽  
Yang Xiujuan ◽  
Yang Henglin
Keyword(s):  
Coal Seam ◽  
Stability Study ◽  
Borehole Stability

Value Optimisation of Future Coal Seam Gas Field Developments Using Horizontal Wells

2015 ◽  
Author(s):  
Nicola Xu ◽  
Petrina Weatherstone ◽  
Naureen Alam ◽  
Xuejun Lin
Keyword(s):  
Coal Seam ◽  
Horizontal Wells ◽  
Coal Seam Gas ◽  
Gas Field

Borehole stability study of coal seam based on orthotropic coal cleats model

2010 ◽  
pp. 457-462
Author(s):  
Wang Baohui ◽  
Yan Xiangzhen ◽  
Yang Xiujuan ◽  
Yang Henglin
Keyword(s):  
Coal Seam ◽  
Stability Study ◽  
Borehole Stability
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