地层倾角测井在大牛地气田水平井区的应用

应用地层倾角测井得到的地层倾角及其倾斜方位角来研究和解决相关地质问题对油气田的勘探开发具有重要意义。对大牛地气田大12-66水平井区地层倾角测井资料开展了沉积环境分析、最大地应力判断、裂缝识别,结合临井资料进行了多井对比分析,确定了水平井区内上、下古生界的不整合面。研究结果表明:下古生界碳酸盐岩和上古生界的太原组、盒二段、盒三段裂缝、微裂缝较发育,最大水平主地应力方向为北东—南西向;细分了太二段和山二段砂体的沉积微相,预测太二2层砂体的加厚方向为北东方向,山二1层砂体的加厚方向为北西方向,山二2层砂体的加厚方向为南东方向。研究成果为水平井布井、井眼轨迹设计提供了所需的地质信息。

Application of dip-log in horizontal wells of the Daniudi Gas Field

The application of stratigraphic dip and dip azimuth data in geological studies are of great significance for exploration and development of oil and gas fields. The dip logs of the horizontal well Da12-66 in the Daniudi Gas Field are used in the analysis of sedimentary setting, definition of the maximum earth stress and identification of fractures. The inter well correlation is also performed by using the dip logs of adjacent wells. The unconformity between the Upper and Lower Paleozoic in this wellblock is recognized. It is revealed that fractures and micro fractures are relatively well developed in the Lower Paleozoic carbonates and the Upper Paleozoic Taiyuan Formation and the second and third members of the Shihezi Formation. The maximum horizontal principle earth stress is in the NE-SW direction. The sedimentary microfacies of the second member of the Taiyuan Formation and the second member of the Shanxi Formation are recognized. It is predicted that the second sand unit in the second member of the Taiyuan Formation thickens in the NE direction. In contrast, the first sand unit in the second member of the Shanxi Formation thickens in the NW direction, while its second sand unit thickens in the SE direction. These understandings provide necessary information for horizontal well placement and well trajectory design.