Challenges in Processing Produced Emulsion from Chemical Enhanced Oil Recovery - Polymer Flood Using Polyacrylamide

Abstract

Polymer flood using polyacrylamide is an effective way to increase oil production in many aged fields. While extensive research and development and field practices have demonstrated the improvements in oil recovery using this technology, the development on effective methods of processing the produced emulsion from polymer flood lags behind. The polymer in the injection fluid, which alters its physical and chemical behaviors, ultimately breaks out with the produced emulsion and changes its physical and chemical characteristics. This leads to tighter emulsions, increased produced water viscosities, stronger chemical interactions, limitations on the processing methods and process conditions, reduced efficiency on current equipment technologies, and even excessive equipment failures and damages. Adding to the processing difficulties is the uncertainty of the break out fluids. As polymer passes through reservoirs, its physical and chemical properties change due to formation absorption, shearing, and chemical reactions. As a result, the produced polymer is different from the injected polymer, and constantly changing during the production cycle. This requires the emulsion processing technologies to be flexible and stable throughout a large operation envelop.

Historical and recent observations in polymer floods: An update review

“…The impact of back produced polymer on production facilities, fluid handling and treatment during polymer flooding have been well documented at lab, bench (i.e. flow loops) and field scale (Al-Kalbani, A., Mandhari, M. S., Al-Hadhrami, H., & Philip, G., 2014b; Al-Maamari, R. S., Sueyoshi, M., Tasaki, M., Kojima, K., Okamura, K., 2014; Bartz & Gotterba, 2015;Jacob et al, 2015;Rambeau, Jacob, Jouenne & Cordelier, 2014;Zheng, Quiroga & Sams, 2011). However, these topics will not be covered here and are out of the scope of this review.…”

“…However, most of the studies documented in the literature mainly focus its attention on emulsion stability and its impact on oil-water separation, water treatment and production facilities (i.e. nutshell filters, heater treaters) due to the back produced polymer (Al-Kalbani et al, 2014;Al-Maamari et al, 2014;Bartz and Gotterba, 2015;Delamaide et al, 2014b;Geremia, and Bennetzen, 2016;Jacob et al, 2015;Rambeau, O., Jacob, M., Jouenne, S., & Cordelier, P., 2014;Wu et al, 2013;Wylde, Slayer & Barbu, 2013;Yang, Zhihua, Xianglong & Shanzhe, 2015;Zheng, F., Quiroga, P., & Sams, G. W., 2011).…”

Screening Criteria and Considerations of Offshore Enhanced Oil Recovery

“…Polymer addition tends to worsen the emulsion problem, which can be a significant problem owing to the severe constraints on offshore facilities. Some of the injected polymer is produced alongside emulsion and increases the emulsion stability and viscosity [50], leading to a long processing time for emulsion breaking on the platform. To reduce emulsion breaking time, a heating method is usually applied in offshore fields.…”

Polymer Flooding of Heavy Oil - From Screening to Full-Field Extension

“…Heater treaters are commonly used for oil-water separation but the presence of polymer can cause fouling of the treaters and failure of some of their components such as fire tubes (Zheng et al 2011). Polymer precipitates on the fire tubes and causes hot spots which eventually lead to the tube failure (Bartz et al 2014); these failures can be frequent and increase operating costs.…”