Mathematical Model for Wells Drilled in Large-Scale Partially FilledCavity in Fractured-Cavity Reservoirs
Lei Gang
Zhang Dongxiao
Yang Wei
Wang Huijie
Abstract：It is significant to explore fluid crossflow rule of various medium in fractured-cavity reservoirs for effective development of crude oil in large-scale partially filled cavity.Based on the filling characteristics of the large size cavity in fractured-cavity reservoir, a fluid flow mathematical model for wells drilled in large-scale partially filled cavity in fractured-cavity reservoir has been proposed in this paper.The Laplace transformation and Stehfest numerical inversion are applied to analyze the crossflow rule in the partially filled cavity.The fluid crossflow characteristic curve for the partially filled cavity has been obtained and studied in this paper.The results show that the process of the flow for the partially filled cavity can be divided into four sections, including the earlier period and middle-early period flow for the crossflow between the matrix system and unfilled part of the cavity, the middle-late period and the later period flow for the crossflow between the filler of the cavity and unfilled part of the cavity.In middle-early flow period, the crossflow between the matrix system and unfilled part of the cavity reaches the quasi steady state.And the crossflow between the filler of the cavity and unfilled part of the cavity reaches the quasi steady state at the later period.Gravity is one of the main factors that influences the typical crossflow characteristic curve,leading to the decrease of the crossflow between the filler and the unfilled part of the cavity.However, the inter-porosity flow between the matrix and the unfilled part of the cavity has no relation with gravity.In addition, the cross flow characteristic curve is greatly affected by filling degree of the cavity, the energy parameters of the filler of the cavity and the energy parameters of the matrix.The methods and results of this research can facilitate further studies on the crossflow characteristics of the partially filled cavity in fractured-cavity reservoirs.
Keywords：fractured-cavity reservoirlarge-scale cavityfilling characteristicscross flow characteristic curveparameter analysispetroleum geology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 1413-1420 )