扶扬油层地层压力场成因

ON THE ORIGIN OF PRESSURE FIELD IN THE FUYANG FORMATION OF THE NE SONGLIAO BASIN

楼章华 曾允孚 高瑞祺 姜传金

Lou Zhanghua Zeng Yunfu Gao Ruiqi Jiang Chuanjin

中国科学院地球化学研究所, 贵阳 550002 2. 大庆石油勘探开发研究院, 黑龙江 大庆 163712

Guiyang Geochmical Institute, Academia Sinica 2. Chengdu College of Science & Engineering

松辽盆地北部东区扶扬油层地层压力场具有明显的分区性。向心流区和越流区为正常压力区;离心流区为高压区;滞留区为低压区。地层压力的形成与演化主要取决于地层孔隙流体的供(液)-排(液)系统。区域水动力场的形成与演化是控制地层压力形成与演化和油气分布的关键因素,此外,天然气的漏失作用、蒸发作用、不稳定矿物的水化作用及地温下降作用,对地层压力场的形成与演化也起着重要的控制作用。

The pressure field in the Fuyang Formation can be obviously divided into 4 areas which are mainly controlled by the origin and evolution of hydrodynamic field.The pressures in centripetal and cross-formational flow areas are normal with the coefficients decreasing from 1.02 to 0.97 along flow direction,while the pressure in centrifugal flow area is dominated by overpressures,with the coefficients decreasing from 1.30 to 1.06 along flow direction,being normal pressures towards its rim,and motionless area is dominated by subpressures with the coefficients of 0.96～0.75.The pressures are related with the recharge-discharge system of pore fluids and pressure field is also influenced by(1)gas escaping,(2)evaporation of water,(3)hydration of unstable debris,such as feldspar and volcanic fragments,(4)unloading caused by bed evasion,and(5)geothermal decrease.

https://doi.org/10.11781/sysydz199501042