轮古7井区奥陶系鹰山组风化壳岩溶发育特征及主控因素分析

发布时间：2018-06-07 03:00

本文选题：风化壳岩溶 + 发育特征　；参考：《西南石油大学》2015年硕士论文

【摘要】：轮古7井区奥陶系地层经历了多期构造运动和长时间的持续暴露,风化壳岩溶作用十分发育,工区勘探现状也表明,高产油气井与古岩溶作用息息相关。本文利用岩心、成像测井、常规测井、钻录井和地震等资料,综合古岩溶学、测井地质学、岩溶地貌学和岩溶水动力学等学科,对研究区风化壳岩溶进行识别,总结其在岩心、常规测井、钻井、电成像测井和地震等方面的特征,建立风化壳岩溶标志,划分岩溶带,分析各带特征；结合地震研究成果,恢复研究区前石炭系古地貌并划分地貌单元,分析不同古地貌单元下的岩溶发育特征；从岩性、古气候、构造断裂、古地貌及古水动力条件等方面,分析岩溶发育的控制因素,预测有利岩溶发育区。论文主要取得以下几点认识： (1)根据从岩心、电成像测井、常规测井、钻井和地震上所总结的特征,引入岩溶相的定义,将研究区岩溶缝洞体主要划分为洞穴相、孔洞相和裂缝相,按照其充填特征,划分出未充填、半充填和全充填缝洞亚相,再根据其充填物性质,划分出泥质、角砾、方解石充填等微相,并建立起电成像测井岩溶相图版。 (2)将研究区单井在垂向上划分为表层岩溶带、垂向渗滤带和水平潜流带,表层岩溶带物性良好局部钻遇落水洞,可见高角度未充填缝和破碎裂缝带,溶蚀孔洞多被垮塌角砾、风化残积物和后期化学物质充填。垂向渗滤带物性较差,可见高角度裂缝,见扩溶现象,但往往充填程度较高；水平潜流带物性条件良好,有利缝洞体大量发育,该带中上部往往发育大型溶蚀洞穴,且溶蚀洞穴上方可见洞顶缝,水平状裂缝和水平状溶蚀孔洞发育,充填物多为泥质和角砾,可见粉砂质泥岩。 (3)结合地震数据,恢复研究区古地貌,将研究区地貌环境划分为峰丛洼地、溶丘洼地和峰丛垄脊沟谷三个三级古地貌单元,之后对不同微地貌单元下的单井发育特征进行精细描述。不同地貌单元的岩溶带特征具有一定差异性,表层岩溶带受微地貌控制,地貌越高垂向渗滤带越厚。根据岩溶缝洞发育特征和充填程度,分古地貌单元和岩溶带对缝洞体类型、岩心及成像测井数据、有效缝洞分布和充填特征进行统计分析,缝洞系统发育以表层岩溶带为最优,次为水平潜流带,垂向渗滤带最差,地貌单元以溶丘洼地最优,次为峰丛垄脊沟谷,峰丛洼地最差。 (4)从岩性、古气候、构造断裂和古地貌及水动力条件四个方面分析岩溶缝洞发育的主控因素,最后总结出出风化壳岩溶缝洞的发育模式,结合地震数据,在平面上预测出受古地貌、断裂和古河流所控制的岩溶缝洞有利发育区。
[Abstract]:Ordovician strata in Lungu 7 well area have experienced multiple periods of tectonic movement and sustained exposure for a long time, and the karstification of weathered crust is very developed. The present exploration situation in the working area also shows that the high-yielding oil and gas wells are closely related to paleokarst process. In this paper, the core, imaging logging, conventional logging, drilling logging and seismic data are used to identify the weathered crust karst in the study area and sum up the karst in the core, combining the paleokarst, logging geology, karst geomorphology and karst hydrodynamics, etc. The characteristics of conventional logging, drilling, electrical imaging logging and seismicity, the establishment of weathering crust karst marks, the division of karst zones, the analysis of the characteristics of each zone, the restoration of the paleogeomorphology of the former Carboniferous system and the division of geomorphological units in the study area, combined with the results of seismic research, The characteristics of karst development under different paleogeomorphic units are analyzed, and the controlling factors of karst development are analyzed from lithology, paleoclimate, tectonic faults, paleogeomorphology and paleo-hydrodynamic conditions, and favorable karst development areas are predicted. The thesis mainly obtains the following understanding: 1) according to the characteristics summarized from core, electrical imaging logging, conventional logging, drilling and seismic, and introducing the definition of karst facies, the karst fracture cavity body in the study area is mainly divided into cave facies, pore facies and fracture facies, and according to its filling characteristics, The subfacies of unfilled, semi-filled and full filled fractures and cavities are divided into microfacies, such as muddy, breccia and calcite filling, according to their filling properties, and the Karst phase diagram of electric imaging logging is established. (2) the single well in the study area is divided vertically into surface karst zone, vertical percolation zone and horizontal subsurface flow zone. The good physical properties of the surface karst zone are partly drilled into a falling water tunnel. It can be seen that the high angle unfilled fracture and broken fracture zone, and the dissolution holes are often collapsed boulders. Weathering residue and late chemical filling. The vertical percolation zone is characterized by poor physical properties, high angle fractures and dilatation phenomena, but it is often filled with high degree, and the horizontal subsurface flow zone has good physical properties and a large number of favorable fractures and caverns, and large corrosion caves are often developed in the middle and upper part of the zone. At the top of the cave, horizontal fractures and horizontal dissolution holes are developed. The filling materials are mostly muddy and breccia, and silty mudstone can be seen. In combination with seismic data, the paleogeomorphology of the study area is restored, and the geomorphological environment of the study area is divided into three paleogeomorphic units, namely, peak cluster depression, peak ridge valley, and peak ridge valley. After that, the development characteristics of single well under different microgeomorphological units are described in detail. The characteristics of karst zones in different geomorphological units are different, the surface karst zones are controlled by microgeomorphology, and the higher the geomorphology is, the thicker the vertical percolation zone is. According to the development characteristics and filling degree of karst fractures and cavities, according to paleogeomorphic units and karst zones, the types of fractures and cavities, core and imaging logging data, effective distribution of fractures and caverns and filling characteristics are statistically analyzed. The surface karst zone is the best system for the development of fractures and cavities. The horizontal subsurface flow zone is the second, the vertical percolation zone is the worst, the geomorphologic unit is the best in the mound depression, the second is the ridge and valley in the peak plexus ridge, and the worst in the peak cluster depression. 4) the main controlling factors of karst fracture and cave development are analyzed from four aspects: lithology, paleoclimate, tectonic fault, paleogeomorphology and hydrodynamic condition. Finally, the development pattern of karst crack and cave in weathered crust is summarized and combined with seismic data. The favorable areas of karst fracture and cavities controlled by paleogeomorphology, faults and ancient rivers are predicted on the plane.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.25;P618.13

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