东营凹陷胜坨地区沙四段地层压力特征及其对储层的影响  

Characteristics of formation pressure and its influences on reservoirs of the fourth member of the Shahejie Formation in Sheng-tuo area of Dongying Depression

作　　者：高建岗 高树新[2] 王风华[2] 李荣权[2] 谭滨田[2] 

机构地区：[1]中国科学院地球化学研究所,贵州贵阳550002 [2]中国石化股份胜利油田分公司胜利采油厂,山东东营257051

出　　处：《油气地质与采收率》2008年第1期35-38,共4页Petroleum Geology and Recovery Efficiency

基　　金：中国石化科技攻关项目“砂岩岩性圈闭含油性定量预测技术研究”(P05013)

摘　　要：选择声波时差资料，根据等效深度法计算了东营凹陷胜坨地区沙四段地层压力，结合实测压力分析了该层段地层压力特征及其对储层的影响。胜坨地区沙四段埋深大于3000m的地层普遍存在超压，压力系数为1．2～1．8。在平面上，胜北断层上升盘沙四段为正常压力，超压主要分布在胜北断层下降盘，并且向凹陷中心压力系数逐渐增大。胜坨地区沙四段超压对储层具有良好的保护和改善作用。超压抑制了压实作用，有利于原生孔隙和已形成的次生孔隙的保存；超压形成过程中有机质演化和粘土矿物转化释放的大量有机酸和二氧化碳促进了不稳定矿物的溶解，形成了次生孔隙；由于超压作用，胜坨地区沙四段储层中普遍发育网络状、炸裂状超压裂缝，有效地改善了储层的渗透能力。Formation pressure of the fourth member of the Shahejie Formation(Es4)in Shengtuo area was calculated by the equivalent depth method based on acoustic interval transit time data.According to the measured pressure,the characteristics of the formation pressure and its influence on reservoirs of Es4 was analyzed.The strata of Es4 in Shengtuo area with more than 3 000m of the buried depth universally appears overpressure,and the pressure coefficients is 1.2-1.8.Laterally the pressure of Es4 formation in the uplifted side of Shengbei Fault is normal.Overpressure mainly distributes in the downthrown wall of the fault,and the pressure coefficients increases gradually to the center of the sag.The overpressure of Es4 in Shengtuo area has protective and improved actions on reservoirs.Overpressure depresses compaction,which is favorable of conservation of primary pores and formed secondary pores.In the course of the development of the overpressure,the organic material evolution and clay mineral transformation release massive organic acid and CO2 which may promote the dissolution of unstable mineral and the formation of secondary pores formed.Owing to the overpressure,reservoirs of Es4 in Shengtuo area universally exists network-like and crack-like overpressure fractures,which efficiently improve the permeability of the reservoirs.

关 键 词：地层压力 分布特征 储层 胜坨地区 

分 类 号：TE112.23[石油与天然气工程—油气勘探]