石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (6): 2012-2025.doi: 10.11743/ogg20250617

• 油气地质 • 上一篇    下一篇

准噶尔盆地玛湖凹陷风城组页岩源-储协同演化机理

孙中良1,2,3(), 李志明1,2,3, 何文军4, 冷筠滢1,2,3, 祝庆敏5, 刘得光4, 王濡岳6   

  1. 1.页岩油气富集机理与高效开发全国重点实验室,江苏 无锡 214126
    2.中国石化 石油勘探开发研究院 无锡石油地质研究所,江苏 无锡 214126
    3.中国石化 油气成藏重点实验室,江苏 无锡 214126
    4.中国石油 新疆油田公司 勘探开发研究院,新疆 克拉玛依 834000
    5.中国石油化工集团有限公司 科技部,北京 100728
    6.中国石化 石油勘探开发研究院,北京 102206
  • 收稿日期:2025-05-12 修回日期:2025-08-19 出版日期:2025-12-30 发布日期:2025-12-25
  • 第一作者简介:孙中良(1993—),男,工程师,页岩油气地质。E‑mail: sunzhl8188.syky@sinopec.com
  • 基金项目:
    国家自然科学基金项目(42090020);国家重点实验室项目(KLP24017)

Mechanisms behind source rock-reservoir coevolution of shales in the Fengcheng Formation, Mahu Sag, Junggar Basin

Zhongliang SUN1,2,3(), Zhiming LI1,2,3, Wenjun HE4, Junying LENG1,2,3, Qingmin ZHU5, Deguang LIU4, Ruyue WANG6   

  1. 1.State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Wuxi,Jiangsu 214126,China
    2.Wuxi Research Institute of Petroleum Geology,Petroleum Exploration and Production Research Institute,SINOPEC,Wuxi,Jiangsu 214126,China
    3.Key Laboratory of Hydrocarbon Accumulation,SINOPEC,Wuxi,Jiangsu 214126,China
    4.Research Institute of Exploration and Development,Xinjiang Oilfield Company,CNPC,Karamay,Xinjiang 834000,China
    5.Science & Technology R&D Department,SINOPEC,Beijing 100728,China
    6.Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 102206,China
  • Received:2025-05-12 Revised:2025-08-19 Online:2025-12-30 Published:2025-12-25

摘要:

为了研究储层演化与烃源岩生烃作用相互影响关系特征,基于准噶尔盆地玛湖凹陷风5井低熟烃源岩样品,开展了孔隙热压生烃模拟实验,系统分析不同演化阶段烃源岩与储层的协同动态演化过程。研究表明:①玛湖凹陷风城组泥页岩生烃演化分为生油早期[模拟镜质体反射率(Easy Ro) < 0.75%]、生油中期(主生油期)(Easy Ro = 0.75% ~ 1.06%)和生油晚期(Easy Ro = 1.04% ~ 1.14%)3个阶段。在生烃作用影响下,储层演化同样具有孔隙发育较差阶段(Easy Ro < 0.75%)、孔隙体积缓慢增加阶段(Easy Ro = 0.75% ~ 0.97%)和孔隙体积迅速增加阶段(Easy Ro = 0.97% ~ 1.14%)的3阶段特征。②风城组页岩生烃演化对储层物性的影响包括次生无机孔隙产生、沥青充填与收缩、生烃增压诱导微裂缝发育、酸性流体溶蚀和自生矿物生成等方面。③储层物性改善可促进页岩生、排烃过程,气/油比升高在较差储层物性条件下则可提高排烃效率。④基于烃源岩与储层的相互作用,可将玛湖凹陷风城组页岩源-储协同演化划分为4个阶段。演化初期(Easy Ro < 0.75%),烃源岩生烃产率较低,储层物性较差。缓慢演化阶段(Easy Ro = 0.75% ~ 0.97%),烃源岩生、排、滞烃产率缓慢增加,储层物性逐步改善。快速演化阶段(Easy Ro = 0.97% ~ 1.06%),储层物性较好,烃源岩生、排、滞烃产率较高。演化后期(Easy Ro > 1.06%),烃源岩生烃产率降低,储层物性较好,排油率增加。当前玛湖凹陷风城组页岩油勘探突破区主体处于快速演化阶段,表明具有优越的资源潜力。

关键词: 气/油比, 源-储协同演化, 生烃模拟, 页岩油, 风城组, 玛湖凹陷, 准噶尔盆地

Abstract:

This study aims to investigate the interplay between reservoir evolution and the hydrocarbon generation of source rocks. To this end, we conduct formation porosity thermocompression simulation experiments of hydrocarbon generation on low-maturity source rock samples from well Feng 5 in the Mahu Sag. Accordingly, we systematically analyze the dynamic source rock-reservoir coevolution process at varying stages. The results indicate that the hydrocarbon generation and evolution of shales in the Fengcheng Formation, Mahu Sag can be divided into three stages: the early (simulated vitrinite reflection, Easy Ro = < 0.75%), middle (Easy Ro = 0.75% ~ 1.06%), and late oil-generation stages (Easy Ro = 1.04% ~ 1.14%), with the middle stage representing the main oil generation period. Under the influence of hydrocarbon generation, the reservoirs correspondingly experienced three stages of evolution: poor pore development (Easy Ro < 0.75%), slowly increasing pore volume (Easy Ro = 0.75% ~ 0.97%), and rapidly increasing pore volume (Easy Ro = 0.97% ~ 1.14%). For shales in the Fengcheng Formation, hydrocarbon generation and evolution influences reservoir properties in five aspects: the generation of secondary inorganic pores, bitumen filling and shrinkage, microfracture development induced by hydrocarbon generation pressurization, acidic fluid-induced dissolution, and the formation of authigenic minerals. Meanwhile, improvements in reservoir properties can promote the hydrocarbon generation and expulsion of shales, while an increase in the gas/oil ratio can enhance the hydrocarbon expulsion efficiency under poor reservoir physical properties. Based on the interplay between source rocks and reservoirs, the source rock-reservoir coevolution of shales in the Fengcheng Formation can be divided into four stages: early, slow, rapid, and late stages. The early evolution stage (Easy Ro < 0.75%), among others, is characterized by a low hydrocarbon yield of the source rocks and poor reservoir properties. During the slow evolution stage (Easy Ro = 0.75% ~ 0.97%), the hydrocarbon yield, hydrocarbon expulsion efficiency, and hydrocarbon retention rate of the source rocks increased slowly, while the reservoir properties improved gradually. The rapid evolution stage (Easy Ro = 0.97% ~ 1.06%) is characterized by favorable reservoir properties and a high hydrocarbon yield, hydrocarbon expulsion efficiency, and hydrocarbon retention rate of the source rocks. The late evolution stage (Easy Ro > 1.06%) exhibits a decrease in the hydrocarbon yield of the source rocks, favorable reservoir properties, and an increasing oil expulsion efficiency. At present, in areas with breakthroughs in shale oil exploration in the Fengcheng Formation, Mahu Sag, the source rock-reservoir coevolution of shales is generally in the rapid evolution stage, demonstrating considerable resource potential.

Key words: gas-oil ratio, source rock-reservoir coevolution, hydrocarbon generation simulation, shale oil, Fengcheng Formation, Mahu Sag, Junggar Basin

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