煤层气井位精细部署的地质工程一体化影响因素分析与科学优化

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

煤层气井位部署与实施方案的研究与论证是煤层气区块开发方案制定的关键环节。通常认为煤层厚度、含气量、埋深等是煤层气井位部署的主控因素,但在实践中发现构造、井间干扰等因素对产气效果的影响也十分显著,煤层气井位部署需要综合地质条件、工程、经济效益等多因素进行科学合理性和全成本投入评价的系统研究。为此,重点介绍了在区块地质条件分析、井距优化、现场施工过程中时常被忽略掉的一些重要因素,并加以分析优化。(1)提出了煤层气井位精细部署与实施的思路与方法。煤层气井位精细部署和科学实施,要充分考虑地质因素、开发效果、经济效益、施工要求等多因素,对区块进行整体规划、精细部署、科学施工和动态调整,主要包括3个阶段任务:开发前精细部署阶段、现场科学实施阶段、开发后动态调整阶段。(2)构造变化对煤层气井产气效果影响较大。分析了沁水南部某煤层气区块内发育小高点、小低点、小鼻状、小断层等次级构造对产气效果的影响,局部小鼻状构造最有利于煤层气富集高产。针对不同构造部位的变化特点,提出了考虑不同井型和次级构造变化的4类13型井网样式分类,适用于不同地质条件的煤层气井型井网部署。(3)模拟研究了多因素影响下的井距优化方案。综合考虑不同井距条件下井间干扰对产气效果的影响、不同井距累计产气量差异、开发井数与产气效果之间的经济效益差异等因素,得出能够实现较好产气效果和经济效益的最优井距大小。(4)提出一种地质工程一体化的井位部署与实施新思路。提出“地质‘块段’划分+井口靶点坐标优化+集中工厂化钻井+强化缝网的‘块段’式压裂”4个步骤的地质工程一体化井位部署和工艺改进优化方法,通过优化井位部署单元,提高钻探效率的同时,利用多口井交替压裂促使裂缝转向,产生更大规模更加复杂的缝网,最大化的沟通储层裂缝和孔隙,以提高部署井的产气效果。文中提出的研究思路和方法可应用于煤层气区块井位部署和现场实施,以不断完善和细化煤层气井位部署实施的内容和全流程,提高煤层气开发方案的科学和合理性,最大化地开采利用煤层气资源。

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.