Reservoir Description Of Liuluoyu Area Chang8Oil Layer In Xiasiwan Oil Field

Liuluoyu area of Xiasiwan Oil Field is located in the southwest of the Luohe river basinGanquan Country in Shaanxi Province. Since the development of Chang8reservoir,there areno comprehensive and systematic research work,and rely mainly on theanalysis of thesurrounding data comparison.So it is lack of guiding theory research. This paper presents asystematic research on chang8oil Layer stratigraphic features,rules of sedimentary,reservoircharacteristics and reservoir characteristics.it is based on the petroleum geology and in the fullinvestigation of the previous research results to provide a theoretical basis for exploration anddevelopment in the study area and surrounding area.Studies show that chang8formation is largely deltaic front parfacies.The sedimentarymicrofacies vertical evolition features of various microfacies combination,mainly underwaterdistributary channel,mouth bar,distal bar,inter distributary bay etc. Chang8reservoir whichhave Low content of quartz and high content of feldspar can be divided into2sand sets and15small layer.The lithology is mainly to gray fine-grained feldspar sandstone.It is low mineralmaturity, high textural maturity and strong diagenesis.The average of single sand layer is5m,porosity mean7.4percent,permeability mean2.8mD.So it’s a tight sandstone reservoirwith low porosity and low permeability. Reservoir sensitivity showed weaker speedsensitivity-weak speed sensitivity,weak water sensitivity,big difference salt sensitivity,weaksoda sensitivity,and high acid sensitivity.The characteristic of crude oil has low density, lowviscosity, low sulfur and low freezing point which with generally better quality.The formationwater type is mainly type CaCl2, shows that the reservoir has good sealing.The reservoirpressure coefficient is0.54,which belongs to low pressure lithologic-structural reservoir orlithologic reservoir,with the dissolved gas drive.