Establishment and Application of Well Pattern Integrity Evaluation Method in Ultra-high Water Cut Stage of Offshore Oilfield

After entering the ultra-high water cut stage, the offshore oilfield development is faced with a series of problems, such as serious water flooding, low well opening rate, large production decline, low utilization rate of water injection and so on. In order to further improve the oil recovery and economic benefit of the oil field, according to the development mode and well distribution characteristics of ultra-high water-cut sandstone reservoir, a comprehensive evaluation method of well pattern perfection of ultra-high water-cut reservoir is established in this paper. Using geological reservoir data, high pressure physical property data, production test data and single well performance data, a comprehensive evaluation system of well pattern adaptability centered on reservoir-single well water drive curve evaluation, improved Shelkachev chart and index statistical analysis is constructed and applied to practical oilfields to carry out the interference evaluation be-tween well patterns, the evaluation of well pattern infill potential and the evaluation of well pattern mining effect. The study shows that the new evaluation system has strong accuracy and practicability, which provides a new idea for the applicability evaluation of well pattern in offshore oilfields in high water cut stage. It can help the reservoir to establish a perfect displacement system of well pattern system, further improve the displacement efficiency and recovery, and provide guidance for the development scheme design of ultra-high water-cut reservoir.