莺歌海盆地东方1-1气田成藏条件及其启示

由于莺歌海盆地众多底辟构造具有相似的成因联系，为研究其底辟构造特殊的天然气成藏条件，通过储层成岩作用、地层水化学分析等，对东方1-1气田进行了剖析，揭示出该气田的成藏地质条件与底辟运动及深部热流体活动息息相关，即：底辟运动为产生背斜构造创造了条件，深部热流体促进了有机质热演化，与底辟运动相伴生的断层与垂向裂隙为深部气源向浅部运移提供了快速通道，多期且具继承性的底辟活动使得天然气成藏期晚，近断层处热流体活动较强烈，临滨亚相粉细砂岩是良好储层，同时具有明显的含气地震信息异常。该盆地内其他底辟构造与东方1 -1气田具有类似的成藏地质条件，在东方1-1气田成功开发的启示下，促进了一批与底辟运动有关的天然气田的发现。

Pooling conditions of gas reservoirs in the Dongfang 1-1 Gas Field,Yinggehai Basin

There is similarity in relevant genesis among those diapiric structures in the Yingehai Basin.Through the analysis of the diagenesis of reservoirs and the hydrochemical property of formation water,it is discovered that the gas pooling conditions in the Dongfang 1-1 Gas Field are closely related to the diapiric and thermal fluid activities.The diapiric activities provided good condition for the formation of anticline structures;while deep thermal fluids stimulated the thermal evolution of organic matters.The concomitant faults and vertical fissures along with the diapiric structure provided a green channel for the deep source gas to migrate to the shallow formations.Multi-periodic and successive diapiric activities resulted in the gas pooling at later periods and fierce activities of thermal fluids near the faults.Finally,the accumulated gas was well preserved in the fine siltstones of the shorefacies,from which the obvious seismic anomaly information was obtained.This study provides reference for more discoveries of gas reservoirs associated with diapiric structures in this basin.