Title: A hybrid embedded discrete fracture model for simulating tight porous media with complex fracture systems

Abstract

Numerical simulation considering complex fracture networks in tight oil reservoir becomes a hot issue during these years. Recently, embedded discrete fracture model (EDFM) shows great advantages over the DFM approaches in both calculation efficiency and simplicity of simulation workflow. EDFM has been widely used in tight oil/gas natural energy or enhanced oil recovery (EOR) development. If a large number of small-scale natural fractures exist in reservoir, the calculation efficiency of EDFM method may decrease. A new hybrid simulation model combining the EDFM and dual porosity (DP) model is proposed. The large-scale fractures are dealt with EDFM method while small scale fractures are dealt with DP model. Considering the low permeability of matrix, transient transfer between matrix and natural fracture is considered. The proposed hybrid model is validated compared with the local grid refinement (LGR) model and EDFM-MINC model, and the difference between transient transfer and pseudo-steady-state transfer effect on production is presented. Finally, two test cases are presented, and the sensitivity of some key parameters are investigated. Result shows that the new simulation model has higher calculation efficiency than LGR and EDFM-MINC models. Meanwhile, it honors a good accuracy. The pseudo-steady-state transfer between matrix and natural fracture leads to bigmore » error in tight oil production performance analysis both in single phase and two phases flow. Low matrix permeability and big matrix size increase the production difference between pseudo-steady-state transfer and transient transfer models. The proposed model can simulate reservoirs considering stochastic permeability distribution.« less

Authors:

Xu, Jianchun ^[1]; Sun, Baojiang ^[1]; Chen, Bailian ^[2]

---

+ Show Author Affiliations

1. China Univ. of Petroleum, Qingdao (China). School of Petroleum Engineering
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computational Earth Science Group

Publication Date:

Mon Oct 29 00:00:00 EDT 2018

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States); China Univ. of Petroleum, Qingdao (China)

Sponsoring Org.:

USDOE; National Natural Science Foundation of China (NSFC); Natural Science Foundation of Shandong Province (China); China Univ. of Petroleum; Fundamental Research Funds for the Central University (China)

OSTI Identifier:

1503192

Report Number(s):

LA-UR-18-30867
Journal ID: ISSN 0920-4105

Grant/Contract Number:  

89233218CNA000001; U1762216; ZR2016EEM30; JQ201716; YCXJ2016018; 18CX02029A

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Petroleum Science and Engineering

Additional Journal Information:

Journal Volume: 174; Journal ID: ISSN 0920-4105

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

97 MATHEMATICS AND COMPUTING; 58 GEOSCIENCES; numerical simulation; discrete fracture model; naturally fractured tight oil reservoir; transient transfer; stochastic permeability