Some ideas on the direction of natural-gas exploration in China in early 21st century

The tasks of natural-gas exploration will be very arduous for China in early 21st centruy, it needs to discover 8 × 1012 to 10×1012m3 of gas in place throughout the country, and to prepare well for opening up a new exploration field. The authors suggest that the main principles that should be oonsidered for exploration direction determination from the high plane of strategy:① the we quality, the conventional resource is the main direction of the study during the first 10 years of the 21st century,and converting going up the low-grade resources (coal-bed gas,tight Sandstone gas, shale gas) is the main task during the second 1o years; ②the exploration degree: the new area and the new field are the main direction for our country to increase natural-gas reserves; ③ the resource distribution: it should take western,central and offshore areas as the main targets; ④the distribution law of large and middle-sized gas fields; and ⑤ the exploration benefit. In recent years, three trends of natural-gas exploration (i. e., the gas reserves from sandstone reservoirs are rising steadily, the proportion of incremental raserves in Mesozoic group and Cenozoic group is growing and tight gas reservoirs have a bright future) Should not be ignored when the exploration direction is selected in the coming years. In this paper, the authors indicate that three main regions that can make the onshore natural-gas exploration of our country in the next 5-10 years developedsustainably: ① foreland basins in central and western pats,including 6 areas where the Manic and Cenozoic foreland basins are developed (Kuqa of Tarim basin, the southwest of Tarim basin, the northwest fringe of Sichuan basin, the west fringe of Ordos basin, the south fringe of Junggar basin, the north fringe of Qaidam basin); ② three large cratonic hasins (Tarim basin, Sichuan basin and Junggar basin ); ③ the deep zone of intracontinental rift basins in the east part of China. The three basins in the west part, two basins in the middle part and offshore areas of China are the main directions for the gas exploration in early 21st century; Songliao basin and bohai Bay basin should be considered as the basins for both gas exploration and oil exploration.