非常规储层压裂井全周期产量递减模型及递减特征

Entire-time production decline model and decline characteristics of fractured wells in unconventional reservoirs

魏新辉,张翼,吴忠维,苏映宏,崔传智,陈业详

中国石化胜利油田分公司油气开发管理中心，山东 东营 257100 中国石化石油勘探开发研究院，北京 100083 中国石油大学（华东）石油工程学院，山东 青岛 266580

Oil and Gas Development Management Center, Shengli Oilfield Company, SINOPEC, Dongying 257100, China Petroleum Exploration and Development Research Institute, SINOPEC, Beijing 100083, China School of Petroleum Engineering, China University of Petroleum, Qingdao 266580, China

非常规储层压裂井产量递减呈现“L”型特征，即产量递减初期快、后期慢。产量递减初期与后期服从不同的递减规律，单个产量递减类型（Arps递减、幂函数递减、线性递减等）已不能完全描述非常规储层呈现的“L”型递减特征。文中提出全周期产量递减模型，并采用Levenberg￣Marquardt方法实现了模型求解，通过对鄂尔多斯盆地南部H油田压裂井产量数据的拟合，验证了全周期产量递减模型能够较好描述非常规储层产量递减的“L”型特征。研究发现：鄂尔多斯盆地南部H油田HP30压裂井产量递减规律为初期线性递减，后期双曲线递减，且递减指数为0.792；初期递减率对无因次产量曲线形状影响较小，递减指数仅影响产量递减后期；后期递减率和时间系数越大，无因次产量递减速度越快。

The production decline of conventional reservoir fractured wells presents a "L" type characteristic: the production decline fasts at the early stage, slows at the later stage, and the production is tiny at the later stage. A single production decline type (Arps decline, power function decline, linear decline, etc.) can no longer fully describe the "L" type decline feature. This paper proposes an entire-time production decline model and gives the Levenberg-Marquardt method for solving the model. Fitting the production decline data of fractured wells in the H oilfield in the southern Ordos Basin verifies that the entire-time production decline model can better describe the "L" type characteristic of unconventional reservoir production decline. It is found that the production decline of HP30 fracturing wells in H oilfield in the southern Ordos Basin shows a linear decline at the initial stage of production decline, and a hyperbolic decline at the later stage of production decline with a decline rate of 0.792. The initial decline rate has little effect on the shape of the dimensionless production curve. And the decline index only affects the later stage of the production decline. The larger the later decline rate and time coefficient are, the faster the decline of the dimensionless production is.

10.6056/dkyqt202104017