复杂碳酸盐岩层间岩溶储层形成机制与地质模式研究

Carbonate karst reservoirs are widely developed in China, Potential petroleum reservoirs in the carbonate karst reservoirs have become the major exploration targets in marine carbonate formations. Recent research on the genetic mechanism of carbonate karst reservoirs has not been comprehensive,the large fracture-cavity buried hill karst reservoirs has been deeply researched, while the small dissolved pores and cavity interstratum karst reservoirs are left out, which greatly impede petroleum exploration and development for the carbonate karst reservoirs. Therefore, the applicants intend to select the Upper Sinian Dengying Formation in the Sichuan Basin as their main research targets. Based on the fine observation of outcrop、core and thin section, in combination with the high resolution imaging logging and 3D seismic data analysis, detailed studies of the characteristics and sparteial distribution of the giant carbonate interstratum karst reservoirs in Moxi and Gaoshiti regions of the middle Sichuan Basin shall be carried out. On this basis of the high-frequency sequences, sedimentary microfacies, unconformity and structural features of paleo-uplift and burial diagenesis, the main controlling factors for the development of carbonate karst reservoirs are discussed; combining with burial evolution analysis, we will try to illuminate the dynamic and evolutional processes of the formation of carbonate karst reservoirs and also reveal the genetic mechanism of interstratum karst reservoir. We will strive hard to make some significant breakthrough in the theory of carbonate karst reservoirs which will be of help to enhance the level of academic research in this field in China, especially the central and western regions of China with deeply-buried marine carbonate reservoir for petroleum exploration and development are also significant.

碳酸盐岩岩溶储层在我国分布广泛，岩溶型油气藏已成为我国海相油气勘探最主要的目标。目前对碳酸盐岩岩溶储层研究存在不均一性，对以大型缝洞为主的潜山岩溶储层成因机理研究较为深入，而对以小型溶蚀孔洞为主的复杂层间岩溶储层研究较为薄弱，极大地制约了该类油气藏勘探开发成效。本项目拟选择四川盆地灯影组为研究对象，以精细露头、岩心和薄片观察为基础，结合高分辨率成像测井和三维地震资料分析，剖析川中磨溪-高石梯特大型碳酸盐岩岩溶储层特征，查明该区复杂层间岩溶储层储集空间展布；在此基础上从高频层序和沉积微相、不整合和古隆起地貌、埋藏成岩改造等方面探讨岩溶储层发育的主控因素；结合该区埋藏演化史分析，阐明复杂层间岩溶储层形成与改造的动态演化过程，揭示碳酸盐岩层间岩溶储层成因机理，力争在碳酸盐岩岩溶储层地质理论研究方面有所突破。该项目的实施有助于提升我国在该领域的研究水平，同时对我国海相深层油气勘探开发亦具现实意义。

碳酸盐岩岩溶储层在我国分布广泛，岩溶型油气藏已成为我国海相油气勘探最主要的目标。目前对碳酸盐岩岩溶储层研究存在不均一性，对以大型缝洞为主的潜山岩溶储层成因机理研究较为深入，而对以小型溶蚀孔洞为主的复杂层间岩溶储层研究较为薄弱，极大地制约了该类油气藏勘探开发成效。本项目以四川盆地灯影组为研究对象，以精细露头、岩心和薄片观察为基础，结合高分辨率成像测井和三维地震资料分析，查明了研究区碳酸盐岩层间岩溶储层发育特征,研究区岩溶储层孔、洞、缝十分发育，储层可分为3种成因类型，包括丘滩相早期岩溶型储层、早期岩溶叠加后期表生岩溶型储层和其他因素叠加改造型储层。在此基础上分析了该区岩溶作用发育的沉积背景，建立了研究区晚震旦世灯影组高频层序地层格架，剖析了高频层序和沉积微相及对早期暴露岩溶的控制。精细恢复了重点工区关键不整合发育期古地貌，剖析了桐湾期区域不整合对储层发育的影响，研究表明该区在岩溶高地和岩溶上斜坡区岩溶作用强烈，岩溶储层发育较好，岩溶下斜坡和岩溶盆地区岩溶作用发育相对较弱。探讨了成岩作用对层间岩溶储层的叠加改造作用，分析了该区碳酸盐岩岩溶储层发育主控因素和成因机理，该区胶结作用和充填作用对早期层间岩溶起破坏性作用，破裂作用和白云岩化作用总体以建设性作用为主；综合沉积微相、高频层序、区域不整合运动、成岩改造等多方面因素建立了复杂岩溶储层发育地质模式，预测了有利岩溶储层分布区域。项目的研究成果对四川、塔里木盆地海相深层岩溶型碳酸盐岩油气藏勘探选区和开发方案部署具有指导意义，提升了我国在碳酸盐岩储层成因机理和分布预测方面的研究水平。