ABSTRACT
A set of shoreline shallow lakeshore dam sand body TII0 is developed in the mudstone section of Triassic TII oil group in Lunan oil field of Tarim Basin, which is deeply buried, thin in thickness, fast in lateral variation, and difficult in reservoir carving. A comparative analysis of multiple wells revealed that the thinly bedded TII0 sand body is positively correlated with the thickness of the mudstone in the lower section of the thick TII oil formation, and the sedimentary geomorphology is the main controlling factor for the development of the thinly bedded sand body in this area. The pre-depositional micro-geomorphology of the TII0 formation was finely recovered by a combination of well seismic, and several low bumps and shallow shoals were developed before the deposition of the TII0 formation, and the sand bodies were mainly developed in the shallow shoals formed by inheriting the Ordovician subduction channel background. Using the sedimentary micro-geomorphology as a constraint, we constructed a phase-control model and carried out seismic waveform inversion to characterize the spreading of the sand body of the 1–3 m TII0 minor layer, and achieved the identification of this minor layer, and a number of wells implemented accordingly were successful.
