摘要
储层压力及流体性质识别信息是勘探开发过程中不可或缺的地质资料。随钻测压取样技术在面对大斜度井、长裸眼井段等复杂井况条件时具有更好的通过性,即钻即测减少地层浸泡时间和取样时间,支持钻井液循环降低黏卡风险。南海油田部分地层属于高孔隙度低渗透率储层,且钻井过程中存在井筒压差大、钻井液侵入深、井壁不规则等特点,造成测压取样时探针座封困难、地层超压、取样耗时过长等情况。借助随钻测压取样技术在南海某油田的首次成功案例,介绍针对低渗透率地层所作的施工方案,包括选用加长型椭圆探针、针对低渗透率设置测压参数、利用多维度探头实时监控井下流体类型等。最终在泵抽点仅耗时4 h取得了纯度达95%的原油样品,为后续实验室流体特征分析提供原材料。案例证明,通过合理的测压模式、探针类型选择以及针对性的参数预设,能够有效提高测量的时效性和安全性,为海上测压取样测井作业提供参考。
Formation pressure and fluid properties identification are indispensable geological data during the oilfield exploration and development.Pressure test&sampling while drilling technology has better accessibility when facing the complex well conditions such as highly deviated wells and long open hole sections.Logging while drilling(LWD)reduces mud invasion time as well as shortens sampling time.Mud circulation is acceptable while pumping also reduces sticking risk.Some oilfields in the South China Sea are of high porosity and low permeability reservoirs,the downhole has the characteristics such as large wellbore pressure difference,deep mud intrusion,and irregular wellbore walls during the drilling,which caused difficulties in pad sealing,supercharged test and time-consuming during sampling.Based on the first successful case of pressure test&sampling while drilling technology in the South China Sea oilfield,this paper introduces the operation of oilfield developers for low permeability formation,which includes elongated packer application,special parameters setting for pressure test for low permeability,and using multi-dimensional sensors to monitor downhole fluid type in real time,etc.Finally,the crude oil sample are taken with less than 5%contamination after 4 hours pumping,which provides sufficient materials for subsequent laboratory fluid characteristic analysis.The case shows that with reasonable pressure measurement mode,probe type selection and targeted parameter preset,the timeliness and safety of logging can be effectively improved,which can provide a reference for future offshore pressure logging and sampling operations.
作者
吴进波
陈鸣
孙殿强
杜超
周基恒
WU Jinbo;CHEN Ming;SUN Dianqiang;DU Chao;ZHOU Jiheng(Zhanjiang Branch, China National Offshore Oil (China) CO. LTD., Zhanjiang, Guangdong 524057, China;Baker Hughes (China) Oilfield Technology Service CO. LTD., Chengdu, Sichuan 610011, China)
出处
《测井技术》
CAS
2022年第1期22-28,共7页
Well Logging Technology
基金
中海石油(中国)有限公司综合科研课题“双孔介质储层测录井综合评价技术与作业方案优化研究”(YXKY-2021-ZJ-01)。
关键词
流体识别
低渗透率储层
随钻测压取样
测前设计
fluid identification
low permeability reservoir
pressure test&sampling while drilling
pre-job design
