CAJ | 학술논문

煤岩气藏钻井、完井和增产改造等环节，不同类型工作液与储层接触相互作用，必将对储层的应力敏感性产生影响。选取宁武盆地中煤阶煤岩，系统开展了不同类型工作液作用人造裂缝煤样的应力敏感性试验。试验结果表明，人造裂缝煤样应力敏感系数为0.73，工作液作用后应力敏感系数为0.79~0.94。通过应力敏感系数对比分析表明，工作液作用下煤岩的应力敏感性强于致密砂岩和页岩。结合岩石力学试验结果可知，煤岩裂隙发育有利于工作液的侵入，工作液作用后煤岩强度降低使裂缝更容易闭合，强化了煤岩储层的应力敏感性。研究成果可为煤层气井钻完井、增产改造和开采过程中煤层气储层保护提供基础参数。
매암기장찬정、완정화증산개조등배절，불동류형공작액여저층접촉상호작용，필장대저층적응력민감성산생영향。선취저무분지중매계매암，계통개전료불동류형공작액작용인조렬봉매양적응력민감성시험。시험결과표명，인조렬봉매양응력민감계수위0.73，공작액작용후응력민감계수위0.79~0.94。통과응력민감계수대비분석표명，공작액작용하매암적응력민감성강우치밀사암화혈암。결합암석역학시험결과가지，매암렬극발육유리우공작액적침입，공작액작용후매암강도강저사렬봉경용역폐합，강화료매암저층적응력민감성。연구성과가위매층기정찬완정、증산개조화개채과정중매층기저층보호제공기출삼수。
During coal gas reservoir well drilling and completions and stimulations, the contact of different types of working liquid with the reservoir and interaction with each other will impact the stress sensitivity of reservoir. Coal samples tested were cored from moderate coal rank in Ningwu basin, after fracturing, the coal samples were soaked in different working fluids, and then were tested for stress sensitivity by increasing and reducing confining pressure. The results show that stress sensitivity of fractured coal sample is 0.73, the stress sensitivity of core samples with working fluid intrusion is 0.79~0.94, the stress sensitivity of coal is greater than tight sandstone and shale before and after being damaged by working fluid. In combination with rock mechanic test results, the fracture development of coal is favorable to the invasion of the working fluid, after being effected by working liquid coal strength reduces, making crack easier to close and strengthening the stress sensitivity of coal reservoirs. Research results can provide basic parameters for coalbed reservoir protection during coalbed methane well drilling and completion, stimulation and exploitation.