论文部分内容阅读
帕姆谷(Palm Valley)气田于1965年3月被发现,帕姆谷1号井日产天然气11.7×10~5立方英尺,产层是奥陶系的砂岩和碳酸盐岩。在这以后,又钻了五口井,井口流量变化较大,日产量从很少一点达到100万立方英尺,甚至有的超过130×10~6立方英尺/日。 基质孔隙度和渗透率一般都是极低的。通过岩心、测井分析和干扰试验证明,地层中广泛延伸的裂缝系统,是气体主要的渗滤通道。 新钻井(帕姆谷4井,5井和6井)都进行了目标明确的综合性现代电缆测井,以识别裂缝的位置和方位。经综合数据分析,能够确定裂缝的方向和密度对井间的影响以及井口产能的差别。裂缝产状从平行于层理面、且井间可对比的裂缝带变化到与井眼斜交的垂直裂缝或近于垂直的裂缝。 高产井可能与高的裂缝密度有关,帕姆谷气田中的裂缝沿背斜轴向发育,如交切平行或近于平行主剩余应力方位的主裂缝带。
The Palm Valley gas field was discovered in March 1965. The well of the Pamtu 1 well produces 11.7 × 10 5 cubic feet of gas per day, with the Ordovician sandstones and carbonate rocks. Since then, another five wells have been drilled and the wellhead flow has changed considerably, with daily production from just a few hundred million cubic feet and even more than 130 × 10-6 CFM. Matrix porosity and permeability are generally extremely low. Core, log analysis and interference tests show that the fracture system that extends extensively in the formation is the main percolation channel for gas. The new drilling (Pamco 4 wells, wells 5 and 6) conducted a well-targeted and comprehensive modern cable log to identify the location and orientation of the fracture. After comprehensive data analysis, it is possible to determine the effect of fracture orientation and density on the well and the difference in well head productivity. The fracture shape changes from parallel to bedding plane, and the cross-well-contrastable fracture zone changes to vertical or nearly vertical fractures that intersect obliquely with the wellbore. The high-yielding wells may be related to the high crack density. The fractures in the Pam Valley are developed along the anticline, such as the main fractures with parallel or near parallel principal residual stresses.