Proactive Block-Factor Analysis of Oil Field Development

Abstract

This paper concentrates on integrated approach to perform block-factor analysis of oil field development. Particularly a simple and effective method of monitoring of oil field development is proposed. This method permits not only to detect the reasons of production decline and find out problematic wells, but also to forecast the development parameters of oil field, its sections, blocks and cells (elements of waterflooding system).The commonly used method of block-factor analysis is taken as a basis. This approach is strongly worked over, revised and automatized by the development of an integrated program module in VBA programming package. In this paper principles of dividing the oil field into blocks are substantiated, an approach to forecast the liquid production and reservoir pressure is developed, a method of evaluation of the recovery factor, recoverable reserves and oil production forecast using the adjusted displacement water-into-oil curve model is proved. The mathematic base of program module consists of physical processes of oil field development, particularly, models of material balance, filtration equations and PVT-correlations. The realization of this approach come down to sequential performance of following actions: adaptation of material balance model, including the adaptation of PVT-parameters and the definition of timeout value of production response to injection, adaptation of modificated El-Khatib model using real displacement characteristic, forecast and retro-forecast of main parameters of oil field development. The forecast of reservoir pressure permits to calculate the target injection (compensation) level to maintain the required reservoir condition. A block rating approach is developed in order to define the most problematic sections of oil field that require operations to improve the development system effectiveness.A special attention is paid to factor analysis performance. Influence of well stock change, operating factor variation, variation of watercut, liquid rate, reservoir and bottom-hole pressure, well productivity (skin factor) are considered. Factor analysis combining with adjusted displacement curve provides an opportunity to divide oil rate loss by reasons of natural and forward watercut growth.Using of improved approach for oil field development monitoring permits not only to reduce the labor inputs, that are essential for analysis, but to improve the quality of work, to connect the aspects of exploitation of different field areas with geological conditions. It also assists to organize justified and well-timed recommendations to perform workover program, waterflooding system control and to achieve project oil production levels overall.