Research On The Recognition Method Of Single Sandbody Of The Reservoir In Lamadian Oilfield

The reservoir of the Lamadian oilfield is thick, and there are many types of the depositional model , thus the macroscopic heterogeneity of the reservoir itself which is determined by the depositional model is serious and complex. The core analysis data of the of new wells drilled in recent years shows that, nearly 1/3 of the thick oil layer is not washed , there is still a lot of oil remaining, which is mainly distributed in the parts that is not perfect injected and produced in the single sand body, and in the top department of the thick oil layer. Thus, according to research needs of the remaining oil of Daqing oilfield old area during ultra-high water cut period, the research of the reservoir needs continuously in-depth exploration. Studying on the single sand body through causes and configuration features can reflect distribution of the single sand body more accurately in complex deposition modes.Based on modern sedimentology, refered to high-resolution sequence stratigraphy, logging geology, petroleum geology and reservoir geology, we conducted an in-depth study of the stratigraphic framework, depositional model, sedimentary microfacies, characteristics of reservoir layer, identification and distribution of a single sand body. We described respectively the configuration characteristics of the sandy braided rivers single sand body, sand dam ( point bat ), abandoned channel sand body, point bar sand body, low-bending zoster channel sand body, crevasse channel sand body, splay sand body, natural levee sand body, the sand body between distributary, underwater distributary channel sand body, mouth bar sand body, and front sheet, and established conceptual model of the single sand body of the river -delta. By the rule "cycle of comparison, hierarchical control, with different phase, differential treatment" , based on small logging cycle curve shows of dense pattern, we divided the purpose layer of Lamadian oilfield into 13 causes of units, and completed vertical anatomical work of the single sand body. Through the comprehensive core and logging data, we knew that the microfacies types of this area and established the logging facies models of various microfacies.Drawed and described the distribution of a variety of microfacies correctly, in accordance with the depositional models, we described finely the representative depositional model of the intended interval in the north-east block of Lamadian oilfield. We described separately the distribution of large sandy braided river sand body, large-scale low-bending distributary channel sand body, delta-front subaqueous distributary channel, and the deposition characteristics of the transition shap between twig and weight delta sand body, the deposition characteristics of delta front sand sheet.At the same time, we analysed the reservoir heterogeneity and the effect factors of remaining oil, and verified the daptability.of of the division of a single sand body.