留楚油田油气富集规律及开发地质研究

Regularities in the accumulation of oil and gas in Liuchu oil reservoir and a st udy of its development geology.

留楚构造带位于冀中坳陷饶阳凹陷中南部 ,是华北油田 1998至 1999年的重点滚动勘探开发区块。该区生储盖层配套 ,纵向上多层系、平面上普遍含油 ,构造两翼含油层位老且单一 ,核部含油层位新且多 ,断层为主要供油通道 ,油层分布垂直断层剖面上呈牙刷状、平面上呈窄条状。据此 ,认为留楚构造带还有较大的增储潜力。主要从 5个方面论述留楚地区油气富集规律和成藏机理 :两套生油岩为油藏形成提供了较丰富的油源 ;东抬地层与反向正断层配合形成多个构造圈闭 ;河流相沉积使东营组成为有利储盖组合 ;深切烃源岩的断层为油气垂向运移通道 ;构造、储集层、油源的有机配合形成留楚复式油气聚集。运用各种地质资料 ,分析储集层分布特征 ,结合油气分布找出滚动开发的有利潜力区 ,并通过已钻潜力区域总结出潜力类型 。

Liuchu structure belt, located in the central sout h part of Raoyang sag, Jizhong depression, is the main progressive exploration a nd development region in Huabei oil field in 1998—1999. Results of study show t hat there is a good source reservoir seal combination, there are multiple form ations vertically and oil bearing layers areally. Oil bearing layers are relati vely old and seldom in wings but relatively new and multiple in the core part. F aults are the main pathways for oil migration. Oil layers distribute in a tooth brush like form and in the form of narrow belt hor izontally along a profile vertical to the fault. There are relatively large pote ntial in reserve increase. In this paper 5 aspects are dealt with the regulariti es in oil and gas accumulation as well as the mechanism in reservoir forming in Liuchu area: (1) 2 sets of source rocks give abundant oil source. (2) Multiple s tructural traps are given by east uplifting formations combined with all normal faults. (3)River fluvial facies deposition gives a favourable combination of r eservoir and cap rocks in Dongying Formation. (4) Deeply cut faults in source fo rmations give pathways for vertical oil and gas migration. (5) A good coordinati on of structure, reservoir beds and oil source forms the Liuchu composite oil an d gas accumulation. Using all kinds of geological information this paper analyze d the characteristics of reservoir distribution, and combined with the distribut ion of oil and gas pointed out the favourable region for progressive oil explora tion and development and summarized out the types of oil and gas potentials.