塔里木盆地雅克拉断凸东部含气性检测与非构造圈闭分析

发布时间：2018-08-17 17:31

【摘要】：位于塔里木盆地北部的沙雅隆起雅克拉断凸是天然气勘探重点区域。此次研究的库车、轮台三维地震区位于库车坳陷南部前缘斜坡带,沙雅隆起雅克拉断凸东部。该区背斜构造发育,生储盖条件较好,已发现多个构造圈闭油气藏。但随着勘探工作的逐渐深入,研究区大中型构造圈闭基本勘探完毕,非构造油气藏勘探成为一个重要方向。本文以岩心、测井、钻井及三维地震资料为基础,利用地震波高频含气衰减原理,在离散频率域内对地震资料进行分频衰减特征分析。将地震勘探方法与地质学理论相结合,通过与石油地质条件的综合对比识别和评价含气异常区,深入探讨了研究区内下古生界寒武系、中生界侏罗系和新生界古近系气藏存在的可能性,取得了以下成果和认识:轮台三维地震区北部侏罗系超覆斜坡带最厚处约300米,不发育背斜构造。用含气检测方法共发现两个含气异常区。1号异常区面积约20 km2,呈椭圆状分布,异常值较高,约10-20 (无量纲),表明了该异常区良好的含气潜力;2号异常区位于1号异常区南部,面积约10 km2,呈条带状分布,异常值8-15 (无量纲),该含气异常区与地震属性显示的地层和砂体展布范围一致,准确性较高。综合考虑不整合面上地层超覆和上倾尖灭及石油地质条件,认为1号异常区可能为岩性上倾尖灭气藏,2号异常区可能为地层超覆气藏。库车三维地震区下古生界海相寒武系碳酸盐岩广泛发育,储层类型以溶蚀孔洞为主。该区检测发现3号含气异常区,面积约10km2,异常值约14-20 (无量纲),异常范围北部边界受断裂控制,与断裂延伸方向基本一致,属于构造-岩性圈闭气藏。库车三维区新生界库姆格列木群砂体广泛分布,分频含气衰减方法所检测异常区位于河道砂体分布区域,与断裂、构造线等无明显关系,通过与石油地质条件综合分析,认为该区异常可能由低速膏盐岩或者砂岩少量含气引起,不具备成藏条件。此次研究提出了一种新的非构造圈闭预测方法,实际资料的对比分析显示其可信度较高,对今后的非构造圈闭油气勘探可以提供一定帮助。
[Abstract]:The Jacques uplift protruding in the northern Tarim Basin is the key area for natural gas exploration. The three dimensional seismic zone of Kuqa and Luntai in this study is located in the front slope zone of Kuqa depression in the eastern part of the Yak-pull uplift of Shaya uplift. The anticline is well developed, and several structural traps have been discovered. However, with the deepening of exploration work, the exploration of large and medium-sized structural traps is basically completed in the study area, and the exploration of non-structural oil and gas reservoirs becomes an important direction. Based on the core, logging, drilling and 3D seismic data, the attenuation characteristics of seismic data in discrete frequency domain are analyzed by using the principle of high frequency gas-bearing attenuation of seismic wave. Combining seismic exploration method with geological theory, the lower Paleozoic Cambrian in the study area is deeply discussed through the comprehensive comparison with petroleum geological conditions to identify and evaluate the gas bearing anomaly area. The possibility of the existence of Mesozoic Jurassic and Cenozoic Paleogene gas reservoirs has been obtained as follows: the Jurassic overlying slope zone in the northern part of Luntai seismic area is about 300 meters thick and the anticline structure is not developed. Two abnormal gas bearing regions were found by gas detection method. The area of anomaly area 1 is about 20 km ~ 2, with an ellipsoidal distribution, and the abnormal value is about 10-20 (dimensionless), which indicates that the anomaly area has good gas-bearing potential, and anomaly area No. 2 is located in the south of anomaly area No. 1. The area is about 10 km ~ 2, and the abnormal value is 8-15 (dimensionless). The gas bearing anomaly area is consistent with the distribution range of strata and sand bodies shown by seismic attributes, and the accuracy is high. Considering the stratigraphic overlying, updip pinning and petroleum geological conditions on the unconformity surface, it is considered that the No. 1 anomaly area may be lithologic updip pinnacle gas reservoir, and the No. 2 anomaly area may be stratigraphic overlying gas reservoir. The Lower Paleozoic marine Cambrian carbonate rocks are widely developed in Kuqa three dimensional seismic area. The gas bearing anomaly area No. 3 is found in this area, with an area of about 10 km ~ 2 and an anomaly value of 14-20 (dimensionless). The northern boundary of the anomaly is controlled by the fault, which is basically consistent with the extension direction of the fault and belongs to the tectonic-lithologic trap gas reservoir. In Kuqa three-dimensional area, the sand bodies of the Cenozoic Kumgarimu group are widely distributed, and the abnormal areas detected by the method of gas attenuation with frequency distribution are located in the distributional area of channel sand bodies, which have no obvious relationship with faults and structural lines, etc. Through comprehensive analysis with petroleum geological conditions, It is considered that the anomaly in this area may be caused by low velocity gypsum salt rock or sandstone with a small amount of gas, which is not suitable for reservoir formation. In this study, a new method for prediction of non-structural traps is proposed. The comparative analysis of actual data shows that the method is highly reliable, which may be helpful to the exploration of non-structural traps in the future.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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