摘要
按气田勘探应抓准宏观控矿规律的思路,此文以实钻资料为基础,并应用水文地质学的渗流理论,对控制气藏分布的气水分异、构造圈闭、岩溶水水侵等主要因素进行了分析论证,指出:阳新统岩溶裂缝性气藏是主要挖潜方向,“平衡钻进”理论不适用于裂缝性气藏。
Dachiganjing structural belt in the east margin of the Sichuan Basin which is com-posed of reversed linear high anticlines and hidden linear low anticlines under the reversedwing is a successful example in trapping gas in the main structure and the hidden structureunder the circumstances that the high anticlines have been denuded partially and subjectedto karst immersion on the shallower part.The main gas-bearing beds are Carboniferoussoluble-pore dolomites and karst fissure limestones of the Permian Yangxin Series,the lat-er will be the main exploration target in after years The gas pools are mainly controlledby structural trap and gas-water differentiation distributed above-2500m in the mainstrucutre and above-4100m in the hidden structure.Scatters seriously the gas in the gas-bearing dolomites and limestones of the first member of Triassic Jialingjiang Formationdue to water immerion.The distribution of gas pools is dominated by“Water-immerionwindow”,structural trap and gas-water gravity differentiation,so gas is primarilypreserved in the south plunging end of the main structure.The main difficulty for pre-exploration is hard to identify the structures formed by steep dipping beds through the seis-mic prospecting,thus the localities of exploration wells are almost always inaccurate.Ifwe could set the well localities on high positions to the best of one's ability,the efficiencyof success would be able to raise.Since the hidden low anticline which is closely related tothe reverse of steep wing was formed late,the gas has less scatter and abundant reserve,it will be one of the main areas for gas exploration.Water of hydration differs from gra-vity water in physical properties,so their preservati on conditions and moving regularitiesare different.It is undoubtedly inappropriate to lump together the two when analyse the pressure field and gas-water relationship.As gas-producing fracture is a kind of linearmedium,the“balance drilling”theory is not suitable for fracture gas pools.If we couldprepare a kind of well-controlled device of high property and sufficient safety and developgas-obtaining technique from gush,we would be able to make a new breakthrough in theexploration of fracture-type gas pools.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
1990年第4期367-369,共3页
Oil & Gas Geology
