ANALYSIS OF GROUND STRESS IN THE SOUTHERN PART OF JUNGGER BASIN AND DISCUSSIONS OF THE RELATED ISSUES

The direction of the biggest horizontal stress in the southwestern part of Jungger Basin is NNE, and that in the central part is SN, that in the eastern part is NNW or NW. Remained tectonic stress, present tectonic stress, depth of the layers and lithology are the main factors that control the present tectonic stress field. We discussed the impact of tectonic stresses on the occurrence of abnormal pressure, the distribution of oil and gas and drilling process on the basis of analysing the present tectonic stress field. Relatively high tectonic pressure is in favor of the closing of the opened faults, and the overpressured upper layers suggest that the underlying reservoirs are well capped. However, overpressured layers and high tectonic pressure will cause significant difficulties in drilling processes.