摘要
为了准确求取无声波测井的裂缝性煤层地应力模型,以沁水盆地北缘煤层气井为研究目标,通过大量室内力学试验测试了煤岩力学参数。结合声波时差测井数据与深侧向电阻率测井、自然伽马测井、密度测井数据之间的关系,数据拟合建立了声波时差模型,并采用压后压力降落G函数曲线、时间平方根曲线和双对数函数曲线预测了煤层压裂裂缝闭合压力;基于试验结果、声波时差模型、预测的闭合压力、压裂破裂压力及水平地应力模型综合反演得到了沁水盆地北缘煤层的地应力模型;对目标井区地应力进行预测。结果表明:预测最大和最小水平地应力误差分别仅为0.5 MPa和0.6 MPa。该方法实现了无声波时差测井条件下裂缝性煤层地应力模型的计算。
In order to accurately obtain a geostress model of the fractured seam with non acoustic logging,based on the coalbed methane wells in the north edge of Qinshui Basin as the study object,great indoor mechanics tests were applied to measure the mechanics parameters of coal and rock.In combination with the relationship between sonic time difference logging data and data from the deep lateral resistivity logging,natural gamma-ray logging and density logging,the data fitting was applied to establish a sonic time difference model.The pressure breakdown G Function curve after the pressurization,time square root curve and Double Logarithm Function curve were applied to predict the closure pressure of the seam fractured cracks.Based on test results,sonic time difference model,predicted closure pressure,fractured crack pressure and horizontal geostress model,a comprehensive inversion was conducted to have the geostress model of the seam in north edge of Qinshui Basin.A prediction was conducted on the geostress in the target well block.The results showed that the errors of the maximum and the minimum horizontal geostress predicted were only 0.5 MPa and 0.6 MPa respectively.The method could realize the calculation of the geostress model for the fractured seam under the condition of the non sonic time difference logging.
作者
陈峥嵘
刘书杰
张滨海
彭成勇
李莹莹
CHEN Zhengrong;LIU Shujie;ZHANG Binhai;PENG Chengyong;LI Yingying(China National Offshore Oil Corporation Research Institute,Beijing 100028,China)
出处
《煤炭科学技术》
CAS
北大核心
2018年第10期136-142,共7页
Coal Science and Technology
基金
中海石油(中国)有限公司资助项目(YXKY-2016-ZY-08)
关键词
煤层气
声波时差
地应力
闭合压力
构造应变系数
coalbed methane
sonic time difference
geostress
closure pressure
tectonic strain coefficient
