摘要
准确确定致密砂岩油充注孔喉下限有助于正确认识致密油成藏。对四川公山庙油田致密砂岩油充注孔喉下限进行理论推导和实验测试。源储界面致密油充注受生烃增压作用明显,基于流体力学作用间平衡关系和油藏实际参数,理论推导源储界面充注孔喉直径下限为29.06nm;储层内部充注力学机制与源储界面不同,生烃增压对流体充注的直接作用较弱,界面的力学推导过程不适用,而通过对实际砂岩样品进行环境扫描与能谱联测的方法确定储层内部的孔喉直径下限为59.66nm。结合致密砂岩储层压汞分析,应用充注孔喉下限确定源储界面附近的含油饱和度为69.5%;储层内部的含油饱和度为60.4%。含油饱和度预测值与公山庙油田致密砂岩实测含油饱和度相一致,对不同部位的孔喉下限的研究结果可为致密砂岩油分布规律和目标评价提供理论依据和预测方法。
Accurate determination of the oil-charging threshold throat plays an important role in recognizing the oil accumulation process. The oil-charging threshold of throats in tight sandstone in Gongshangmiao Oilfield of Sichuan Basin has been studied by means of theoretical calculation and of the observation using environmental scanning and energy spectrum (ESEM) in this paper. Based on the fluid mechanical equilibrium,the calculated theoretical threshold near the interface between source rocks and reservoirs is 29.06 nm. Because the direct influence of the oil-generation overpressure on the fluid is not as strong as the one near the interface,the threshold in the middle of tight sand reservoirs was measured as 59.66 nm with ES- EM instead of mechanical analysis. Connecting the thresholds with the mercury injection capillary pressure test (MICPT) on tight sandstone reservoirs,it is predicted that oil saturation near the interface between source rock and reservoir and the one in the middle of reservoirs are 69.5% and 60.4% respectively,which are in good accordance with the well test. Researches on thresholds in different parts of reservoirs could provide a theoretical basis for the study on tight oil charging mechanism and a practical method for tight oil saturation prediction and play assessment.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2014年第5期693-700,共8页
Natural Gas Geoscience
基金
中国石油天然气股份有限公司科技攻关项目(编号:2011A-0203
2011B-0403
2012E2601-01)
中国石油勘探开发研究院院级项目(编号:2012Y-062
2011Y-004)
国家科技重大专项(编号:2011ZX05003-001)联合资助
关键词
公山庙油田
致密砂岩油
充注孔喉下限
理论计算
实验测试
Gongshanmiao Oilfield
Tight sand oil
Oil-charging threshold throat
Theoretical calculation
ESEM measurement