CAJ | 학술논문

从川中地区震旦系油气成藏过程中相态变化的角度分析勘探前景.运用磷灰石裂变径迹和Easy Ro化学动力学模型联合计算了寒武系烃源层、震旦系储层所经历的热史和寒武系烃源岩的生烃史.寒武系烃源岩具有明显的二次生烃的特征,从而导致震旦系储层多期次的油气充注.震旦系储层的烃类流体相态因温度、压力的变化发生了从油→凝析油和湿气→油裂解成因的天然气→液态甲烷(水溶态)→气态甲烷等一系列的相态变化.其中对成藏具有重要意义的是,因温度变化导致油裂解为天然气过程中所形成的异常高压致使水溶气的形成,并因后来构造隆升所引起水溶气的脱溶过程.该区寒武系烃源岩生烃强度大,震旦系古构造的形成和发展与生烃过程配置较好,表明川中地区震旦系具有良好的勘探前景.
종천중지구진단계유기성장과정중상태변화적각도분석감탐전경.운용린회석렬변경적화Easy Ro화학동역학모형연합계산료한무계경원층、진단계저층소경력적열사화한무계경원암적생경사.한무계경원암구유명현적이차생경적특정,종이도치진단계저층다기차적유기충주.진단계저층적경류류체상태인온도、압력적변화발생료종유→응석유화습기→유렬해성인적천연기→액태갑완(수용태)→기태갑완등일계렬적상태변화.기중대성장구유중요의의적시,인온도변화도치유렬해위천연기과정중소형성적이상고압치사수용기적형성,병인후래구조륭승소인기수용기적탈용과정.해구한무계경원암생경강도대,진단계고구조적형성화발전여생경과정배치교호,표명천중지구진단계구유량호적감탐전경.
This paper analyzes the exploration prospect of Sinian in the centre of Sichuan Basin from hydrocarbon accumulation history. The apatite fission track analysis and Easy Ro (vitrinite reflectance) chemical kinetic model are carried out to compute the thermal history of the Cambrian source rocks and Sinian reservoirs. The hydrocarbon generation history of the Cambrian source rocks indicates that secondary generating hydrocarbon has ever happened obviously. These events lead to multiple phase hydrocarbon fluid charge in the Sinian reservoirs. With the change of temperature and pressure of formation, the phase of hydrocarbon fluid in the Sinian reservoirs has produced a series of changes as follows: oil → condensate oil and wet gas → natural gas due to oil cracking to gas → liquid methane (water soluble gas)→gaseous methane. With regard to the hydrocarbon accumulation, the most important processes are the formation of water-soluble gas resulting from generating abnormal overpressure in the process of oil cracking to gas, and the exsolution of the water soluble gas with the change of temperature due to the structural uplift. In this area, the Cambrian source rocks have a strong hydrocarbon-generating capacity, and the formation and development of the Sinian palaeo-structure match well with the hydrocarbon-generating history. All these evidences indicate that there is a great exploration prospect in Sinian of Central Sichuan Basin.