Study On Distribution And Potential-tapping Of Remaining Oil In Chang4+5Reservoir Of Danba Area

Chang4+5reservoir of Danba oil field in Ordos Basin was taken as the study object in this thesis.The fine reservoir description, reservoir dynamic analysis, reservoir engineering, numerical simulation and petroleum engineering were integrated applied.Performance and static state were united to deeply research sedimentary facies, microtectonics, reservoir characteristic, geological reserves, residual oil law and corresponding digging measures, and to develop a set of research ideas and technologies on the remaining oil distribution and potential-tapping measures in the lithology in Ordos Basin, which will offer reference to the similar reservoir development.The main researches are as follows:1. Microtectonics of each subzone of chang4+5were researched systematically and deeply, mierostrueture distribution was described finely, meanwhile mechanism of gas-oil inrichment and oil remaining distribution was studied.2. The reservoir depositional microfacies, the sandbody distribution, the main controlling factors and rock-electrical characteristic of different sedimentary body were firstly researched systematically and finely under small well space of300metres, of which indicate that lower chang4+5was delta front intrafacies and upper chang4+5was deltaic plain intrafacies, and the sandbody distribution of former was controlled by lake waves and its scale was more than the latter.3. The four property relations and recognition of oil layer, water layer, dry layer was studied systematically, to deternine the reserves calculating parameters of each layers and complete the original geological reserves.The remaining recoverable reserves and use of degree was estimated under the condition of EOR standardizing of water flooding.4. In order to obtain a more accurate result of numerical simulation, the evaluating method of geological model was established using co-simulation modeling method in the stage of3D reservoir model constructing and using well match rate to evaluate quantitatively the reliablility of geological model in the stage of history match.5. The production changes of oil well, dynamic of water flooding, effective characteristics of water flooding, flooding law were studied systematically, and the reasons that it was difficult to maintain production and productiion was low were indictated deeply. As the same time, dominant factors of oil remained distribution was discussed.6. A historical match and prediction on liquid production, oil production and production degree were made to define the characteristics of remaining oil distribution and pressure filed of lays of chang4+5reservoirs through numerical simulation. Base on these studies of geological description, dynamic analysis and numerical simulation, the adjustment and development strategy of the remained oil is made out. After the implementation of program, significant production increasing and good economic benefits are brought into play for the filed.