Unified Density-based Production Data Analysis Under Multiphase Flow Conditions
Restricted (Penn State Only)
- Author:
- Tran, Kien
- Graduate Program:
- Energy and Mineral Engineering (PHD)
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- July 28, 2022
- Committee Members:
- Gregory King, Major Field Member
Shimin Liu, Major Field Member
Matthew Rau, Outside Unit & Field Member
Luis Ayala H, Chair & Dissertation Advisor
Jeremy Gernand, Professor in Charge/Director of Graduate Studies - Keywords:
- Production Data Analysis
Multiphase Flow - Abstract:
- Production Data Analysis is undoubtedly one of the most crucial practices in reservoir engineering, provides meaningful applications in wells performance prediction, reservoir characterization and resource estimation. While considerable work has been published in the literature focusing on PDA for single-phase oil and dry gas reservoir, those for gas-condensate gas reservoirs with multi-phase flow characteristics are yet to be fully explored and understood. The complexity of multi-phase flow environment poses a radical challenge in adapting previously developed analytical models for single-phase flow. The most popular approach using pseudo-variables concept requires a complete relationship between pressure and phase saturation. In the particular case of gas-condensate reservoir, the commonly use Constant Volume Depletion data failed to represent the actual phase behavior of the unsteady-state flow region under boundary-dominated flow condition. Consequently, the calculation multiphase pseudo-pressure is affected by severe deviations, resulting in erroneous analysis. The purpose of this study is two-fold. We first aimed to investigate the multiphase flow behavior of multiple binary mixtures using fundamental thermodynamic concepts. Secondly, we presented the Unified Density-based (UDB) approach as a comprehensive PDA technique, applicable for different types of hydrocarbon resource, including oil-water, gas-water, and gas-condensate reservoir. For each type of resource, insights from our thermodynamic study are incorporated in the UDB approach to deliver highly accurate analysis in an efficient manner. In the application for gas-condensate reservoir, a novel saturation-pressure profile is proposed to improve the multiphase pseudo-pressure calculation and better represent the physics of multi-phase flow. Following that, we presented a predictive model with capability of simultaneously forecast producing gas-oil ratio along with future flowrate for a wide-range of gas-condensate reservoir, from lean gas to liquid-rich gas.