中国天然气评价勘探的几个问题

SOME PROBLEMS ON NATURAL GAS EVALUATION AND EXPLORATION IN CHINA

本文重点分析了有关我国天然气评价、勘探的四个问题:天然气勘探、开发的基本方针,在东部陆相油区内找气,南方海相碳酸盐岩构造复杂区的评价选区,低孔渗致密层气的勘探。

Four problems on the evaluation and exploration of natural gas resources in Chinaare discussed in this paper.1.Exploration stratagem of matural gas:our development policy is“to explore large-,medium-and small-size gas fields simultanneously,and to give consideraton tolong-,medium-and short-term planning”.2.Prospecting natural gas in oil-rich provinces:Songliao and Bohai Bay basins arethe largest oil-bearing basins in China,and are relatively rich in different types of naturalgas resources.Many medium-and small-size gas fields(pools)have been discovered inboth basins.There are not only bright prospects,but also favorable conditions for explor-ing natural gas in the oil-rich provinces.Oil and gas can be explored simultaneously withlow cost,high efficiency and high profit,and they can be explored and utilized in the nearfuture.3.Resource evaluation and determination of exploration areas in structurally com-plex carbonate area in Southern China:an “overall geologic evaluation”should firstly bemade in the area Where the carbonates have been croped out,and then choose some areasfor key researches and experiments on exploration methods.The principles for favorableexploration area determination are(1)keeping away from the anticlinorium and focusingon the synclinorium;(2)preserving hydrocarbon better in low thermal regions than inhigh thermal regions.4.Gas exploration in low-porosity and low-permeability tight formation:we havesuccessful experiences and unsuccessful lessons in exploring tight formation gas.Reason-able caution should be taken in exploration deployment for such gas.