Research and exploration on production decline curve model of shale oil and gas

Abstract

The inconsistency of shale oil and gas production decline prediction methods leads to the inconsistency of shale oil and gas production decline curve prediction. Aiming at this problem, this paper introduces five commonly used shale oil and gas production decline curve models: typical curve model based on ARPS model, modified hyperbolic decline model, power index model, mixed typical curve model and Duong model. The prediction methods of uncertainty typical curve model and certainty typical curve model are studied. The results show that the production history of multistage fractured horizontal wells is not long enough, and it is difficult to verify the production decline in the later stage, so it is suggested to use hyperbolic decline model or modified hyperbolic decline model. Aiming at the blocks with production data, a prediction method of uncertain shale oil and gas production decline based on production performance data is proposed. The results are in good agreement with the actual production data, and can be used in oilfield production allocation. Due to the characteristics of shale reservoir such as nanometer pore size, nadasi permeability, strong heterogeneity and high fracturing strength of long horizontal wells, the output of shale oil and gas wells varies greatly. The typical production decline curve obtained by deterministic method has certain risk.