dong zuo ao xian di shen zhi mi sha yan cheng yin yu shen ceng qi kan tan
Author(s): Yuan Zhengwen
Pages: 14-22
Year: 1993 Issue: 1
Journal: Oil & Gas Geology
Keyword: 东濮凹陷; 深层气; 成岩作用; 致密砂岩;
Abstract: The gas reservoirs of deep beds in Dongpu Depression are considered to be sublacus-trine fan which underwent diagenetic changes under abnormal high pressure condition.Because of the shielding of the overlying sealed beds,the separated materials includingS~(4+),Fe~(2+),Ca~(2+) and Mg~(2+) etc.ions contained in mudstone clay minerals were not easyto move out,thus causing intensely ferrian carbonate-precipitation,replacement,quartzsecondary enlargement nearby.The permeability of sandstone dropped rapidly,so inter-granular pores, intragranular pores and micropores became the main preserving spaces ofthe reservoirs,and hence the reservoirs characterized by 1.high capillary-pressure;2.highaquifer-satuation;3.high pressure-sensitivity and 4.high heterogeneity.It is suggestedthat a systematic study including geological and geophysical researches,the techniques ofwell-drilling and well-completion should be carried out to improve the success of gas ex-ploration.
Pages: 14-22
Year: 1993 Issue: 1
Journal: Oil & Gas Geology
Keyword: 东濮凹陷; 深层气; 成岩作用; 致密砂岩;
Abstract: The gas reservoirs of deep beds in Dongpu Depression are considered to be sublacus-trine fan which underwent diagenetic changes under abnormal high pressure condition.Because of the shielding of the overlying sealed beds,the separated materials includingS~(4+),Fe~(2+),Ca~(2+) and Mg~(2+) etc.ions contained in mudstone clay minerals were not easyto move out,thus causing intensely ferrian carbonate-precipitation,replacement,quartzsecondary enlargement nearby.The permeability of sandstone dropped rapidly,so inter-granular pores, intragranular pores and micropores became the main preserving spaces ofthe reservoirs,and hence the reservoirs characterized by 1.high capillary-pressure;2.highaquifer-satuation;3.high pressure-sensitivity and 4.high heterogeneity.It is suggestedthat a systematic study including geological and geophysical researches,the techniques ofwell-drilling and well-completion should be carried out to improve the success of gas ex-ploration.
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