Quantitative prediction of shale gas sweet spots based on seismic data in Lower Silurian Longmaxi Formation, Weiyuan area, Sichuan Basin, SW China

Autor: Qingcai ZENG, Sheng CHEN, Pei HE, Qing YANG, Xiaolong GUO, Peng CHEN, Chunmeng DAI, Xuan LI, Shaohua GAI, Yu DENG, Huaxing HOU
Jazyk: English<br />Chinese
Rok vydání: 2018
Předmět:
Zdroj: Petroleum Exploration and Development, Vol 45, Iss 3, Pp 422-430 (2018)
Druh dokumentu: article
ISSN: 1876-3804
DOI: 10.1016/S1876-3804(18)30047-8
Popis: Abstract: Sweet spots in the shale reservoirs of the Lower Silurian Longmaxi Formation in Weiyuan 201 Block of Sichuan Basin were predicted quantitatively using seismic data and fuzzy optimization method. First, based on seismic and rock physics analysis, the rock physics characteristics of the reservoirs were determined, and elastic parameters sensitive to shale reservoirs with high gas content were selected. Second, data volumes with high precision of the elastic parameters were obtained from pre-stack simultaneous inversion. The horizontal distribution of key parameters for shale gas evaluation were calculated based on the results of rock physics analysis. Then, the fuzzy evaluation equation was established by fuzzy optimization method with test and logging data of horizontal wells with similar operation conditions. key parameters affecting the productivity of horizontal wells were sorted out and the weights of them in the sweet spots quantitative prediction were worked out by fuzzy optimization to set up a sweet spots evaluation system. Three classes of shale gas reservoirs which including two kinds of sweet spots were predicted with the above procedure, and the sweet spots have been predicted quantitatively by combining the above prediction results with the testing production. The testing results of 7 verification wells proved the reliability of the prediction results. Key words: Sichuan Basin, Lower Silurian Longmaxi Formation, shale gas, sweet spots, quantitative prediction, fuzzy optimisation
Databáze: Directory of Open Access Journals