保德区块煤粉产出特征及其影响要素剖析  

Analysis of characteristics of coal fine production and its influence factors in Baode block

作　　者：孟文辉 张文 王博洋 郝帅 王泽斌 潘武杰 MENG Wenhui;ZHANG Wen;WANG Boyang;HAO Shuai;WANG Zebin;PAN Wujie(PetroChina Coalbed Methane Co.,Ltd.,Beijing 100020,China;Institute of Unconventional Oil and Gas,Northeast Petroleum University,Daqing,Heilongjiang 163318,China;School of Resources and Geosciences,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国石油煤层气有限责任公司,北京100020 [2]东北石油大学非常规油气研究院,黑龙江大庆163318 [3]中国矿业大学资源与地球科学学院,江苏徐州221116

出　　处：《油气藏评价与开发》2023年第4期441-450,共10页Petroleum Reservoir Evaluation and Development

基　　金：国家自然科学基金项目“低阶煤储层煤粉产出对差异流体作用的响应及其机制”(42002186)。

摘　　要：煤粉问题在煤层气开发中日益凸显,合理控制煤粉运移与产出,是煤层气井稳产、高产的关键。目前对于保德区块煤粉运移产出规律认识不清,制约了本区部分井煤层气高效开发。基于上述问题,借助煤粉驱替物理模拟实验,探究不同地质与工程条件下煤粉产出特征,并阐明地层水流速、矿化度、气水比、有效应力等因素对其控制作用。研究表明,排水阶段较小的流速下产出煤粉量极少,裂缝中煤粉发生运移但是堆积在出口处,形成煤粉“滤饼”;当超过临界流速后,煤粉大量产出,较大幅度的压力波动能将出口处堵塞的煤粉冲出。地层水矿化度越大,携带煤粉运移能力越强;单气相流动无法有效驱替煤粉运移产出,50∶50气水比的两相流具有更强的携带煤粉的能力。随着加载在煤岩上的有效应力增加,产出液中煤粉的质量浓度不断下降,且出口端的憋压压力具有相同的下降趋势,但驱替压差在不断增加。研究结果为现场开展煤粉防治措施提供数据和理论基础。The issue of coal fine production is increasingly prominent in the development of coal-bed methane.Implementing appropriate measures to control the migration and production of coal fines is crucial for achieving stable and high production of coal-bed methane wells.However,the characteristics of coal migration and production in the coal seams of Baode block remain unclear,which hinders the efficient development of coal-bed methane in some wells in this area.To address the problem of coal fine production in coal-bed methane development,core flooding experiments were conducted to investigate the migration and production characteristics of coal fines concerning influencing factors such as formation water velocity,salinity,gas-water ratio,effective stress,etc.The experimental results revealed that during the drainage stage,the amount of coal fines produced at low formation water flow is minimal,with coal fines moving within fractures and accumulating at the outlet,forming a coal powder filter cake.However,when formation water flow surpasses the critical flow,a significant amount of coal fines is produced.A substantial pressure fluctuation can flush out the coal fines obstructing the outlet.Furthermore,the salinity of the formation water plays a role in carrying coal powder,with higher salinity increasing its transport capacity.While single gas phase flow is not effective in displacing the coal fine migration and production,two-phase flow with a gas-water ratio of 50∶50 exhibits a stronger ability to carry coal powder.The concentration of coal fine in the produced liquid continued to decline with the increase of the effective stress loaded on the coal,Similarly,the holding pressure at the outlet follows a downward trend,but the displacement pressure difference increases.The research findings provide essential data and a theoretical basis for implementing on-site prevention and control of coal fine production.

关 键 词：保德区块 煤粉 产出特征 流速 气水比 有效应力 

分 类 号：TE37[石油与天然气工程—油气田开发工程]