Abstract:

Miniature differential accumulation exists in carbonate fracture system in Southeast Sichuan.The formation,distribution and transformation of the accumulation were controlled by horizontal torsion stress field;its existence is related to considerable tectonic stress field remained.The miniature defferential accumulation is composed of migration drive system,accumulation drive system and passage system.The driving force is caused by the closure strain contractancy of regional major tensile fracture;water and gas accumnlations result from the tensile strain dilatancy of the local tensile fracture.The geological model of this kind of accumulation in South Sichuan includes height transformation and fault displacement types,which could describe the distribution regularity of oil and water,and provide theoritical basis for discovering hidden fracture reservoirs.