Experimental Study of In‐Situ CO₂Foam Technique and Application in Yangsanmu Oilfield

Abstract

The Yangsanmu oilfield of Dagang is a typical heavy oil reservoir. After the maximum primary production (waterflooding), more than half of the original oil is still retained in the formation. Therefore, the implementation of an enhanced oil recovery (EOR) process to further raise the production scheme is inevitable. In this work, a novel in‐situ CO2 foam technique which can be used as a potential EOR technique in this oilfield was studied. A screening of gas producers, foam stabilizers and foaming agents was followed by the study of the properties of the in‐situ CO2 foam systems through static experiments. Core‐flooding experiments and field application were also conducted to evaluate the feasibility of this technique. The results indicated that the in‐situ CO2 foam system can improve both the sweep and displacement efficiencies, due to the capacity of this system in reducing oil viscosity and interfacial tension, respectively. The EOR performance of the in‐situ CO2 foam system is better than the single‐agent and even binary system (surfactant‐polymer) flooding. The filed data demonstrated that the in‐situ CO2 technique can significantly promote oil production and control water cuts. These results are believed to be beneficial in making EOR strategies for similar reservoirs.

Retracted: Visualization of Low-Permeability Natural Core Carbon Dioxide Immiscible Flooding Flow Characteristics

“…The reflectivity of tracer particles after coating can reach more than 90%. In addition, particles with larger diameter can increase the scattering light intensity, thus improving the particle imaging quality [11][12].…”

Experimental study on the enhanced oil recovery by in situ foam formulation

“…Therefore, to overcome these problems and expand the foam application, in situ CO 2 foam method has been sought to replace the current conventional injection method. The potential benefits of this new method mainly including the following three aspects: (a) equipment and material aspect, ISCF system does not rely on the transportation pipeline and natural CO 2 source . Besides traditional foam injection equipment requires high pressure capacity, ISCF can reduce the dependence on high pressure equipment, which contributes to the application and promotion in offshore oil fields.…”

“…The potential benefits of this new method mainly including the following three aspects: (a) equipment and material aspect, ISCF system does not rely on the transportation pipeline and natural CO 2 source. 33,34 Besides traditional foam injection equipment requires high pressure capacity, ISCF can reduce the dependence on high pressure equipment, which contributes to the application and promotion in offshore oil fields. (b) Injection effect aspect, ISCF not only has better swept volume and cleaning efficiency than gas flooding, water alternating gas (WAG) flooding and carbonated water injection (CWI), but also unblock the contaminated formation to some extent.…”

Solution Properties and Displacement Characteristics of in situ CO2 Foam System for Enhanced Oil Recovery

“…For single‐liquid injection, CO 2 producer solution (bicarbonate or carbonate) is injected into the reservoir, which then decomposes to generate CO 2 under reservoir conditions. Single‐liquid injection was successfully applied in the Yangsanmu oilfield (China), the Samotlor oilfield (Russia), and so on (Jin et al, ). The generation of CO 2 is as follows: …”