| Author's Name: XIE Jirong, ZHAGN Zili, ZHONG Yuan, YAN Wei, LI Kunyu, HE Yuan,
ZHAO Like, LONG Hongyu, ZHANG Baoshou, QIAO Yanping
Abstract：Recently, a high-yield industrial gas flow of 231×104 m3 was obtained from the test of Dengying |
| Recently, a high-yield industrial gas flow of 231×104 m3 was obtained from the test of Dengying Member 2 of
Well PT101, which refreshed the test production record of the Dengying Formation in Sichuan Basin, and further
demonstrated that the deep marine carbonate rocks in the paleouplift of Sichuan Basin have huge natural gas reserves and
exploration potential. Based on the latest drilling logging-lithology, seismic and test data, a new round of research is
carried out on the oil and gas bearing geological conditions of Dengying Formation in central-northern area of Sichuan
Basin, so as to further clarify the exploration potential of platform margin belt of the Dengying Member 2 in centralnorthern
area of Sichuan Basin and guide the follow-up exploration deployment. The results show that: (1) The platform
margin deposits of Dengying Member 2 gradually widened and thickened from south to north in central-northern area of
Sichuan Basin, with an overall width of 40-130 km and a thickness of 650-1 000 m. (2) The reservoirs of the Dengying
Member 2 in central-northern area of Sichuan Basin are mainly algal dolomites of platform margin, with secondary
dissolution pores, holes and fractures, and high-quality reservoirs are overlapped in a large area, with an average porosity
of 3.6 % and an average permeability of 3.6×10-3 μm2. (3) The source-reservoir spatial combination of Dengying Member
2 in central-northern area of Sichuan Basin is excellent. Several large fault controlled structural-lithologic traps were
found in Zhongjiang-Penglai block by using seismic prediction technology. Nowadays, exploration has confirmed that
well areas of PT1 and ZJ2 have independent gas-water interface, which is far lower than that in Gao-Mo area, and
lithologic and structural-lithologic gas reservoirs under the background of large monoclinal structure are developed. It is
concluded that the platform margin of Dengying Member 2 in central-northern area of Sichuan Basin has advantageous
sedimentary background, good reservoir development conditions and superior allocation relationship of natural gas
reservoir forming factors. At present, a breakthrough has been made in Zhongjiang-Penglai block in the southern section
of the platform margin belt. In addition, seven traps have been preliminarily described in the north section of the platform
margin of Dengying Member 2, with a total area of 380-1 300 km2 and a predicted trap resource of (1 900-6 500) ×108 m3.
The platform margin of the Dengying Member 2 in central and northern area of Sichuan Basin is an important strategic
new zone for the discovery of the next trillion gas area in Dengying Formation. |
