Cheng-Dong Yuan

The Kinetic Analysis of Oxidized Oil During the High Pressure Air Injection by Thermal Kinetic Analysis

Studying the changing of the oil property with injected air is the prerequisite to apply the HPAI technique in heavy oil reservoir. For this purpose, the oxidation experiments have been carried to study the influence of pressure on heavy oil analyzed by thermogravimetry and differential scanning calorimetry. The results indicated that the oxidized oil with lower activation energy is easier to react with the oxygen. So the higher pressure has positive influence on the coke deposition with stable combustion front. Sufficient coke will bring the possibility for application of HPAI technique without ignition devices in heavy oil reservoirs.

The Kinetic Analysis of Coke Formation Under Differential Air-oil Ratio During High Pressure Air Injection

For studying the heavy oil property change during high pressure air injection process, constant temperature oxidation tube experiments have been finished to study the influence of air-oil ratio on the oxidation process with thermoanalysis methods. The results presented an increasing amount of formation coke was contained with the air-oil ratio increment. When the air-oil ratio reached 200:1, the oxidation process was promoted and the oxide was identified as “coke” with smell. Based on the Arrhenius method, it indicated the air concentration has positive influences on the coke deposition conducive to form and sustain stable combustion front.

Utilisation of multiple gas injection to enhance oil recovery for fractured-cavity carbonate heavy oil reservoir

Gas injection has been proven to be a valuable enhanced oil recovery (EOR) process for light oil reservoirs and ordinary heavy oil reservoirs, but it was rarely proposed as an EOR process for fractured-cavity carbonate heavy oil reservoir. This study aims to investigate the feasibility of the gas injection based on flooding and cycle stimulation method with respect to enhancing oil recovery for fractured-cavity carbonate heavy oil reservoir. Thus, a representative physical model of core was designed, and some gas flooding and cyclic gas stimulation experiments were conducted. The experimental results show that gas injection can enhance the oil recovery in fractured-cavity carbonate reservoir and carbon dioxide is the optimal injected gas in this study. Also, gravity drainage plays an important role in fractured-cavity carbonate reservoir besides the various recovering mechanisms in conventional reservoir. In addition, Tahe heavy oil has a strong capacity of oxygen consumption due to the high content of polar compound. [Received: May, 1, 2015; Accepted: February 29, 2016]

The effects of interfacial tension, injection rate, and permeability on oil recovery in dilute surfactant flooding

ABSTRACT Surfactant flooding as a potential enhanced oil recovery technology in depleted reservoirs after water flooding has been documented for several decades and has attracted extensive attention. This research explored the effect of interfacial tension among crude oil and surfactant, injection rate, and permeability on oil recovery in dilute surfactant flooding. The results indicated that the additional oil recovery increased with the reduction of the interfacial tension and the increase of the permeability. The additional oil recovery increased and later decreased with the increase of injection rate. The research is instructive for surfactant flooding application for enhanced oil recovery.