原油裂解气资源评价的理论技术创新与评价应用——以四川盆地震旦系—寒武系为例  

Theoretical and technological innovation and evaluation application of crude oil cracking gas resource evaluation——Taking the Sinian—Cambrian of Sichuan Basin as an example

作　　者：郭泽清[1] 赵文智[1] 谢增业[1] 王志宏[1] 姜华[1] 李剑[1] 朱光有[1] GUO Zeqing;ZHAO Wenzhi;XIE Zengye;WANG Zhihong;JIANG Hua;LI Jian;ZHU Guangyou(Research Institute of Petroleum Exploration and Development,Petrochina,Beijing,100083)

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《地质论评》2024年第1期309-329,共21页Geological Review

基　　金：国家自然科学基金资助项目“环青藏高原盆山体系动力学与天然气富集机理”(编号:U22B6002)的成果。

摘　　要：四川盆地震旦系—寒武系天然气资源丰富。近年来,在四川盆地川中古隆起和北部斜坡区先后获得了两个万亿级大气区的重大发现。为了明确该领域天然气的资源规模以及未来的勘探方向和创建一套切实可行的原油裂解气资源量的评估方法,本次研究基于该区天然气为古油藏原油裂解的基本认识,按照干酪根生油,再到古油藏裂解生气的技术路线对原油裂解气的资源量进行计算。应用成因法,采用PetroMod 3D盆地模拟软件,输入地层等厚图、岩相古地理图、烃源岩综合评价图、剥蚀量展布图以及生油动力学参数图版,建立整个盆地的三维地质模型,并切分为5个区块分别计算生油量,然后探讨了石油运聚系数、石油裂解率、天然气散失率以及寒武系石油运移的分配系数,并创建了天然气散失系数计算公式。在以上基础上,恢复了盆地及5个构造单元的生油史,并明确了古油藏形成的关键时刻,最终得到全盆地震旦系—寒武系常规天然气资源量为13.43×10^(12)m^(3),其中寒武系为5.43×10^(12)m^(3),震旦系为8.0×10^(12)m^(3)。并指出除了川中地区以外,川南和川东具有巨大的勘探潜力,尤其是位于川南地区德阳—安岳裂陷槽两侧的台缘带和台内颗粒滩是下一步勘探的现实领域。本次研究在理论创新和勘探实践中都具有重要意义。Objectives:The Sinian—Cambrian natural gas resources are abundant in Sichuan basin.In recent years,two giant gas-accumulating areas with two trillion cubic meters reserves have been discovered in the central Sichuan palaeo-uplift and northern slope areas of the Sichuan Basin.In order to clarify the scale of natural gas resources and future exploration directions in this field,and to create a practical and feasible evaluation method for crude oil cracking gas resources,this study was conducted.Methods:Based on the basic understanding that the natural gas in this area came from the cracking of crude oil in ancient oil reservoirs,the resource amount of crude oil cracking gas was calculated according to the technical route of kerogen generating oil and then cracking gas from ancient oil reservoirs.The formation thickness maps,lithofacies palaeogeography maps,comprehensive evaluation maps of hydrocarbon source rock,erosion thickness maps and oil generation dynamics parameter plates were inputted to PetroMod 3D basin simulation software,and the 3D geological model was established to calculate oil generation in five primary tectonic units,Then,the oil migration and accumulation coefficient,oil cracking rate,gas loss rate and the partition coefficient of Cambrian oil migration were discussed,and the calculation formula of natural gas loss coefficient was established,eventually the conventional natural gas resources of the Sinian and Cambrian were obtained.Results:The oil generation history of the basin and five primary tectonic units has been restored,and the critical moment of the formation of ancient oil reservoirs has been clarified.The conventional natural gas resources of the Sinian Cambrian in the entire basin and five primary tectonic units have been obtained.Conclusions:In Sichuan Basin,oil generation quantity of the Cambrian was 1.05×10^(12) t,with 0.33×10^(12) t for the Sinian.From the perspective of the whole basin,there is a small amount of oil generation in Ordovician,and a large amount of hydrocarbon ge

关 键 词：四川盆地 震旦系—寒武系 原油裂解气 资源量 原油裂解率 天然气散失率 

分 类 号：P618.13[天文地球—矿床学]