复杂钻井泥浆侵入条件下的夏盐地区低饱和度油藏的流体性质识别方法  

Identification Method of Fluid Properties for Low Oil Saturation Reservoir inXiayan Area under the Condition of Intrusion by Complex Drilling Mud

作　　者：武洪菊 刘锐 张永波 彭龙 黄会会 连志刚 刘鑫焱 韩学辉[2] WU Hong-ju;LIU Rui;ZHANG Yong-bo;PENG Long;HUANG Hui-hui;LIAN Zhi-gang;LIU Xin-yan;HAN Xue-hui(Luliang Oil Production Plant,PetroChina Xinjiang Oilfield Company,Karamay 834000,China;School of Geoscience,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油新疆油田分公司陆梁采油厂,克拉玛依834000 [2]中国石油大学(华东)地球科学与技术学院,青岛266580

出　　处：《科学技术与工程》2024年第34期14632-14640,共9页Science Technology and Engineering

基　　金：国家自然科学基金(U1562108)。

摘　　要：陆梁油田夏盐地区西山窑组发育低含油饱和度油藏,低电阻率油水同层和高电阻率水层并存,应用深探测电阻率等测井响应识别油水同层、水层的符合率仅为67%。本次研究从低电阻率油水同层和高电阻率水层的成因出发,通过构造对流体性质敏感的含油性指数并绘制交会图建立了测井识别流体性质方法。首先,分析了不同井的电阻率与岩性、物性、含油性、钻井泥浆电阻率、泥浆浸泡时间的相关性,发现淡水泥浆电阻率的井间差异大以及侵入是造成低电阻率油水同层和高电阻率水层并存的主要原因。其次,假设深电阻率探测范围内地层水为泥浆滤液,定义R_(t)/R_(mf)为含油性指数以减弱钻井泥浆滤液矿化度的差异以及侵入的影响。最后,绘制R_(t)/R_(mf)与密度交会图作为流体性质识别图版,由试油证实的油水同层和水层刻度确定7为油水同层的电性下限。结果表明:新解释的夏盐18井的油水同层、盐1175井的含油水层与试油结论吻合较好,该方法解释流体性质的符合率从67%提高到92%,取得了较好的应用效果。Xishanyao Formation reservoir belongs to low oil saturation reservoir because of its low oil saturation and high water production rate.The coincidence rate with the employment of logging response including true resistivity is 67%because of the coexistence of low resistivity oil-water layers and high resistivity water layers.A fluid identification method was developed based on the cause analysis of low resistivity oil-water layers and high resistivity water layers,the definition of oil content index,and the cross-plot.Firstly,some factors affecting resistivity such as lithology,porosity,permeability,oil saturation were analyzed and it was found that the origin of coexistence of low resistivity oil-water layers and high resistivity water layers was the difference of low salinity drilling mud among the wells and intrusion.Secondly,R_(t)/R_(mf) was defined as oil content index to weaken the affection on resistivity from the salinity difference of drilling mud among the wells and intrusion based on the assumption that all the brine was mud filtrate within the detection range of true resistivity.Finally,the R_(t)/R_(mf)-density cross-plot was chosen as fluid identification cross-plot and 7 was calibrated as the lower limit of R_(t)/R_(mf) of oil-water layers by the results of oil testing.The results shows good application effect that oil-water layer in well Xiayan 18 and the water with oil layer in well Yan 1175 were identified matched the results of oil testing and the coincidence rate was increased from 67%to 92%.

关 键 词：低饱和度油藏 淡水泥浆 侵入 流体性质 R_t/R_(mf) 

分 类 号：TE312[石油与天然气工程—油气田开发工程]