Ansai Oilfieid Development Later Period, Adjust And Optimize Technology Well Network Research

This paper focuses on the blocks which has been in water flooding for a long time in Ansai Oilfield. On the basis of analyzing three geological regular patterns and remained oil distribution pattern, this paper discusses the well pattern evaluation, well pattern adjustment potential analysis and optimizing of well pattern and well spacing in different kinds of reservoirs. Finally, a scientific system of well pattern adjustment method was established.Through research of this project, some innovative outcomes are obtained as follows:1. Through core experiments and coring data, observation on the change of microcosmic penetrating pattern is analyzed, combined with relative permeability curve, injection and production and dynamic monitoring, the permeating pattern of the oil field is obtained; 2. With the combination of reservoir engineering, reservoir simulation prediction, remained oil distribution and dynamic analysis, remained oil distribution is analyzed.3. An integrated well pattern evaluation approach is established with the analysis of initial well production, production decrease rate, water cut increase, inter-well inference and reservoir simulation, in order to evaluate the effectiveness of well pattern adjustment; 4. Well pattern adjustment is optimized with the approaches of reservoir engineering, reservoir simulation and other similar methods.5. Through integrated evaluation and contrast, the potential of Ansai oilfield is 2102 infill wells, production of 1.691 million tons, and the conversion of 63 production wells to injection wells.The result of this project can be employed in determining the suitable well spacing, deploying infill wells and guiding the well pattern optimizing, therefore is serviceable in the effective development of Ansai Oilfied, and can provide reference for oilfields of similar characteristics.