Study On Regularity Of The Remaining Oil Control In Chang6Reservoir Of Zichang Oilfield

Zichang oil field is located in the township zichang county of shaanxi province stable flow mud bay bay township-temple temple ditch area, thickness of the oil with, oil level difference is bigger, and the reservoir lateral and longitudinal change drastically, complicated oil-water relationship, the well testing, production, production water cut difference is bigger also. Based on the leader of yanchang6reservoir group as the research object, collected30Wells and120representative production Wells all sorts of dynamic and static data, at the same time focus on representative Wells core are described in detail and pictures, to analyze representative core sample test. And according to the lithologic time mark in the strata within the isochronous stratigraphic framework analysis and comparison.Research shows that extension of top-down subdivided into10reservoir group, and chang6reservoir is further divided into Chang6-, Chang62, Chang63, Chang64four subgroups according to reservoir. Smaller oilfield stable district chang6reservoir tectonic activity is relatively stable, no obvious fracture and fold structure movement, sedimentation also have inheritance; Nose-like uplifts mainly along the85-127Wells are distributed in a line east-west, uplift, modest, generally less than5m, nose-like uplift and the relationship between oil and gas is not obvious. This district chang6reservoir is a set of rivers into the lake after the lake delta sedimentary formation, source mainly comes from the north east direction. The porosity of single well in this area is8.0-10.0%, permeability is0.4-1.2×10-3μm2,strong heterogeneity, belongs to low permeability reservoirs. Chang62and Chang63is the main oil-bearing strata in this area, its distribution is controlled by the sedimentary microfacies, good in distributary channel and distributary channel flank reservoir development, and between distributary bay microfacies area, shore and shallow lake reservoir thinner even pointed out. Long lake into period caused on far-flung regions, hydrocarbon generation, the construction of chang6delta peak form of repeatedly superimposed channel sand body of the belt is one of the most important for the reservoir, and the chang61periods of delta plain faces floodplain marsh, is to provide a good cap rock. Rich in oil and gas, evaluate the oil-bearing blocks, chang62and chang63reservoir subgroups have delighted many customers and the most favorable exploration area of considerable area class-I areas, can be used as a recent target of exploration and development.