鄂尔多斯盆地F区力学特征及地应力分析

Mechanical Characteristics and Crustal Stress Analysis of F Block in Ordos Basin

地层的力学特征是井身结构设计和钻井液设计的重要基础。以鄂尔多斯盆地F区扩径较高的延长组为研究对象,通过三轴压缩实验、巴西劈裂等室内实验得到其抗压强度、弹性模量、泊松比、内聚力、内摩擦角和抗张强度等静态岩石力学参数,通过声波时差、密度等计算其动态岩石力学参数,建立动态和静态岩石力学参数之间的转化关系。通过工区的压裂资料,反演出延长组的地应力分布,进而计算出地层的坍塌压力和破裂压力,建立地层的三压力剖面,为延长组的井身结构设计和钻井液的设计提供参考。

The mechanical characteristics of formation are the important basis of well structure design and drilling fluid design.Taking the Yanchang Formation in the F block of Ordos Basin as the research object,the static rock mechanics parameters such as compressive strength,elastic modulus,poisson s ratio,cohesion,internal friction angle and tensile strength were obtained by tri-axial compression test and Brazilian splitting test.The dynamic rock mechanics parameters were calculated by acoustic time difference and density,and the transformation relationship between dynamic and static rock mechanics parameters was established.Based on the hydraulic fracturing data in the work area,the crustal stress distribution of Yanchang Formation was inverted,the collapse pressure and fracture pressure of the formation were calculated,and the three-pressure profile of the formation was established,which provides a reference for the well structure design and drilling fluid design of Yanchang Formation.