Analysis and scientific optimization of geological engineering integration influen-cing factors for precise deployment of coalbed methane well locations

ZHAO Xin; DUAN Shichuan; WANG Ziliang; ZHANG Shangkun; DING Lian; LI Congcong; WANG Weichao; YIN Yalei; DONG Changle

doi:10.12438/cst.2023-1001

Abstract：The research and demonstration of coalbed methane well location deployment and implementation plan is an important link in the formulation of coalbed methane block development plan.It is generally believed that the thickness,gas content,and burial depth of coal seams are the main controlling factors for the deployment of coalbed methane wells.In practice,it has been found that structures,inter well interference,and production processes also have a significant impact on gas production.The deployment of coalbed methane wells re-quires a systematic study of scientific rationality and full cost investment evaluation based on multiple factors such as exploration,devel-opment,and economic benefits.Therefore,this article focuses on analyzing and studying some important factors that are often overlooked in the geological conditions of the block,optimization of well spacing,and on-site construction process.①This article proposes ideas and methods for the precise deployment and implementation of coalbed methane well locations.The precise deployment and scientific imple-mentation of coalbed methane well locations require full consideration of multiple factors such as geological factors,development effects,economic benefits,and construction requirements.Overall planning,precise deployment,scientific construction,and dynamic adjustment of the development block are required.The fine deployment of coalbed methane well locations mainly includes three stages of tasks:pre development fine deployment stage,on-site scientific implementation stage,and post development dynamic adjustment stage.②Structur-al changes have a significant impact on the gas production efficiency of coalbed methane wells.This article analyzes the impact of second-ary structures such as small high points,small low points,small nose shaped,and small faults on gas production in a coalbed methane block in the southern part of Qinshui.Local small nose shaped structures are most conducive to the enrichment and high production of coalbed methane.Based on the characteristics of changes in different structural parts,4 types of 13 well pattern classification were pro-posed considering different well types and micro structural changes,which are suitable for deployment of coalbed methane well pattern un-der different geological conditions.③This article simulates and studies the optimization plan of well spacing under the influence of mul-tiple factors.By comprehensively considering the impact of inter well interference on gas production efficiency under different well spa-cing conditions,the difference in cumulative gas production between different well spacing,and the economic benefit difference between the number of development wells and gas production efficiency,the optimal well spacing size that can achieve good gas production effi-ciency and economic benefits is obtained.④This article proposes a new approach to the deployment and implementation of integrated geological engineering well locations.Process improvement and optimization adjustment of coalbed methane wells can be achieved through four steps:"geological block division,optimization of wellhead target coordinates,factory drilling,and"block fracturing"to en-hance inter fracture interference.This method can improve drilling efficiency.At the same time,this method can improve the gas produc-tion efficiency of deployed wells,utilizing alternating fracturing of multiple wells to form inter fracture interference,generating larger and more complex fracture networks,and maximizing communication between reservoir fractures and pores.The research ideas and methods proposed in the article can be applied to the deployment and on-site implementation of coalbed methane blocks.By continuously improv-ing and refining the deployment and implementation of coalbed methane well locations,we aim to improve the scientific and rational de-velopment plan of coalbed methane and maximize the exploitation and utilization of coalbed methane resources.