RESERVOIR GEOLOGICAL AND DEVELOPMENT CHARACTERISTICS OF TIGHT AND SUPERTIGHT MARGINAL OIL FIELDS——A CASE STUDY OF CONTINENTAL OIL FIELDS IN THE MESOZOIC BASINS OF NORTH LIAONING PROVINCE

The marginal oil field is a common type of oil fields in continental strata.As there are small reserves,low accumulation energy and poor reservoir quality in oil fields,many defficulties emerge when developing this kind of oil fields.Recent years,a lot of continental tight and supertight marginal oil fields were discovered in the Mesozoic (Upper Jurassic) basins of North Liaoning and Nei Monggol,among which Majiapu,Liao-1 district and Bai 3-4 district are three typical tight and supertight oil fields.In this paper,the reservoir characteristics of this kind of marginal oil fields are emphatically discussed,the reason why reservoirs have low permeability is analyzed,and the reservoir dynamic characteristics of tight oil fields are summarized.On this basis,strategies for reasonable development of marginal oil fields are suggested.