The Fault Effects on the Oil Migration in the Ultra-Deep Fuman Oilfield of the Tarim Basin, NW China

Abstract

A giant, ultra-deep (>7000 m) strike-slip fault-related oilfield has been found in the central depression of the Tarim Basin. However, little research has addressed this discovery to understand the fault effects on the oil migration, which constrains the oil exploitation deployment and well optimization. Based on fault modeling and fluid analysis, we present the effects of fault segment on the oil segmentation and migration in the ultra-deep Fuman Oilfield. The results show a distinct fault segmentation and also subsequent variable fault architecture and non-connected fracture network other than a through-going fault zone. There are fault segment-related isolated fractured reservoirs and fluid variation along the fault strike, which indicates that a large oilfield comprises a series of unconnected small oil reservoirs along the fault segments. The fluid segmentation and molecular indicator of dibenzothiophenes reveal that there is a variable petroleum lateral migration along the strike-slip fault segment. The fault segmentation is a major contribution in the varied oil accumulation along the strike-slip fault zone in Fuman Oilfield. This case study suggests that fault segmentation has variable effects on petroleum migration and accumulation along the strike-slip zone.