千米桥潜山油气藏基本地质特征

位于黄骅坳陷北大港构造带的千米桥潜山在 1 998年勘探中获重大突破 ,于奥陶系钻获高产油气流。该潜山为一古残丘背斜山 ,奥陶系上覆上侏罗统—下白垩统 ,缺失石炭 二叠系、三叠系和中、下侏罗统 ,遭受风化淋滤时间长 ,碳酸盐岩目的层中孔、缝、洞均较发育 ,油气分布在距奥陶系顶部 2 0 0m以内的风化壳储集层中 ,油源对比证实 ,油气主要来自板桥凹陷沙河街组。据目前综合分析 ,该潜山油气藏类型为受风化壳控制的带较大油环的高饱和凝析气藏。图 4参 3 (梁大新摘 )

Basic geological characteristics of Qianmiqiao buried hill oil/gas reservoir.

An important exploration breakthrough occurred in 1998 in Qianmiqiao buried hill oil/gas reservoir, Beidagang structural belt, Hanghua sag, i.e. commercial oil and gas flows have been obtained in Ordovician series. This buried hill is an anticlinal paleo remnant hill. Ordovician series is covered by Upper Jurassic Lower Cretaceous while Carboniferous, Permian, Triassic and Medium Lower Jurassic are absent. These formations were subjected to weathering and leaching for a long period of time, so that fractures, fissures, and caves are well developed in these carbonate rocks. Oil and gas distribute in the reservoir beds of the weathered crust 200m down from the top of Ordovician. By oil source correlation it is confirmed that oil and gas came mainly from Shahejie Group, Banqiao sag. According to a comprehensive analysis the oil/gas reservoir is of oversaturated condensate gas reservoir with a fairly large oil ring controlled by the weathered crust.