珠江口盆地惠州26-6烃源岩热压模拟实验及生气潜力

数十年勘探实践表明，珠江口盆地浅水区和深水区商业油气发现呈现“北油南气”的分布格局；随着浅水区中深层勘探不断深入，珠江口盆地珠一坳陷惠州凹陷惠州26-6构造在中生界潜山和古近系获得首个凝析气规模商业发现，引起了大家对珠江口盆地浅水区天然气资源潜力的关注。为客观有效评价珠江口盆地浅水区油型烃源岩生气潜力，选取了惠州26-6文昌组半深湖相暗色泥岩样品（Ⅱ1型）进行了半开放体系下热压模拟实验，研究了珠一坳陷惠州凹陷惠州26洼油型烃源岩在生油气高峰阶段和在不同演化阶段的产油气率，综合分析了惠州26洼油型烃源岩的生排烃模式及生烃潜力；并从烃源岩热演化程度、烃源岩生气潜力及优势汇聚方向等方面分析了惠州26-6油气田的成藏条件。

THERMO-COMPRESSION SIMULATION EXPERIMENT AND GAS GENERATION POTENTIAL ANALYSIS OF HUIZHOU 26-6 SOURCE ROCKS IN THE PEARL RIVER MOUTH BASIN

Exploration practice in the Pearl River Mouth Basin suggests that the distribution of commercial oil and gas discoveries follow a pattern of “oil in north and gas in south”. With the progress in middle and deep exploration in the shallow water area, the first large-scale condensate gas reservoir was discovered in Mesozoic buried hills and Paleogene system of the Huizhou 26-6 structure in the Zhuyi Depression of the Pearl River Mouth Basin, which has raised people's attention to the natural gas resource potential in the shallow water area of the Pearl River Mouth Basin. In order to objectively and effectively evaluate the hydrocarbon potential of oil-type source rocks in shallow water area of the Pearl River Mouth Basin, the semi-deep lacustrine dark mudstone sample (Type Ⅱ1) of the Wenchang Formation in the Huizhou 26-6 was selected to conduct the thermo-compression simulation experiment under a semi-open system. The model of hydrocarbon generation and expulsion are analyzed synthetically with the hydrocarbon potential of the oil-type source rocks, based on the analysis of the peak stages of hydrocarbon generation and the study of oil and gas production rates at different evolutionary stages for the oil type source rocks in the Huizhou 26 sag. In addition, the forming conditions of Huizhou 26-6 oil and gas field are investigated from the aspects of thermal evolution of source rocks, gas potential of source rocks and dominant convergence direction.