High Fidelity High Resolution Processing and High Precision Prediction Techniques for Thin Deep Carbonate Reservoir: A Case Study of Maokou Formation Reservoir in The North Slope of Central Sichuan Basin

In recent years, Maokou Formation in the Sichuan Basin has acquired high production after several well tests, especially JT1 well achieved a strategic breakthrough in the pore-type reservoir of beach facies dolomite in Maokou Formation. It obtained 1.128 million m3/day of high-yield industrial through perforation acidification, which further confirmed that the marginal belt of the second phase of Maokou ring rift has good exploration potential. However, owing to the deep and ultra-deep burial of Maokou Formation, the near-surface and formation absorption attenuation are serious, and the frequency bandwidth of deep seismic data is narrow and the main frequency is low. Under the background of limestone, the physical characteristics of thin dolomite are little different from those of surrounding rock, and the seismic response characteristics are weak. The overall thickness of dolomite reservoirs is thin, with poor physical properties and strong heterogeneity, making it difficult for high-resolution imaging and precise seismic prediction of thin reservoirs. The purpose of this paper is to further clarify the reservoir type and seismic response characteristics of the second member of Maokou Formation (Mao-2 Member), carry out ‘double high’ processing and high-precision prediction around the subtle thin reservoirs, which improve imaging and prediction accuracy of deep or ultra-deep carbonate thin reservoirs. Firstly, the calibration of seismic synthetic record and forward modeling technology are studied to clarify the seismic response characteristics of Mao-2 Member and provide basis for seismic data processing. Secondly, near-surface Q compensation, Q tomography modeling and Q-PSDM high-resolution processing are carried out to compensate the attenuation loss of stratum absorption, recover deep weak signals, and the seismic response characteristics of stratum reflection interface and hidden reservoir of Maokou Formation are more obvious, and strike-slip faults are more clear and reliable. Finally, on this basis, fine interpretation and high-precision prediction are carried out to further improve the identification accuracy of thin reservoir, and a series of ‘double high’ processing and interpretation techniques for deep carbonate thin reservoirs are formed, which can be popularized and applied to high-resolution imaging and high-precision prediction of thin reservoirs. It has good application prospects and promotion value.