Study On Remaining Oil Distribution Of Fan-delta Sedimentary Facies In Medium And High Water-cut Stage

Well logging interpretation was used to evaluate single well remaining oil saturation and remaining reserves abundance in view of distinguishing feature of researched region such as complex structure, quickly variable sedimentary facies, strong aeolotropy, complex hydrocarbon water contact, little core testing data, inlet well close to fault and containing water and press difficult to match that would cause false or inaccuracy numerical modeling result. Remaining oil concentration potentiali- ty was found according to comprehensive analysis combing regional geology,seismic,logging and core analysis data, which provide strong guaranty for oil field development and good example for similar oil field.Layer was carefully compared and multianalzed according to the rule that marker formation controlling and cycle comparing under the dirrect of sequence stratigraphy, sedimentology, petroleum geology, and combining using regional geology,seismic,logging and core analysis data.Fan body was recognized from plane and interspace according to using seismic instantaneous amplitude, instantaneous frequency and instantaneous phase properties. vertical-variability was also recognized according to using the means wavelet alternation of GR well logging. The result indicate it was retrograding sequence in member III at Shahejie formation in Binnan oilfield Bijia block, and four sand layer group can be separated into four delta fan deposition. The vertical sequence of fan-delta front sand and turbidite is established, the sedimentation model of actic region fan-delta and sedimentation evolution characteristics which lake enlarges continuously are also established. At the same time the research indicates that old topography and border contemporaneous fault are most important elements which fan-delta is buildup.Structure feature of in Binnan oilfield Bijia block was nose like structure which was North North East aligement, South South West pitch, steep eastern limb and soft western limb. Microtectonics in Binnan oilfield Bijia block also recognized.Based on cores analyses of coring well, the four properties relationships(i.e., lithology, physical property, conductivity and oil bearing)between conglomerate and glutenite formation were studied; The logging interpretation models of porosity, permeability and oil saturation in conglomerate and glutenite reservoirs with different lithologies were set up. The aeolotropy of reservoir was also analyzed, result indicated that reservoir was belong to high porosity and moderate permeability, lower sand body connectivity, strong aeolotropy.Single well remaining oil saturation was evaluated according to using water flooded layer well logging interpretation, C/O well logging interpretation, produced fluid profile, outcome matching means, effective permeability curve means, saturation and permeability combining water drive curve means, water drive characteristic curve means and reservoir engineering means. Some elements affect remaining oil distribution such as effective thickness, porosity, remaining oil saturation, sedimentation microfacies, structure condition, reservoir aeolotropy, sand body position, well perforation completeness level and injector producer pair level were comprehensive researched using K-means. Many static state heterogeneous factors which controlling remaining oil, such as microtectonics, sedimentation microfacies, physical property heterogeneity, fluid property and many development heterogeneous factors such as the well-net adaptability, coning of oil well, the completeness of water flooding regime were studied. The result indicated some elements such as underwater distributary channel sedimentation microfacies, forward direction microtectonics, strong aeolotropy, sand body boundary position, incomplete well perforation and poor injector producer pair were good for remaining oil to distribute.