Surfactant/Polymer Flooding: Chemical-Formulation Design and Evaluation for Raudhatain Lower Burgan Reservoir, Kuwait

Abstract

Summary Surfactant/polymer (SP) flooding is an enhanced-oil-recovery (EOR) process that can lead to incremental oil recovery through two mechanisms: reducing oil/water interfacial tension (IFT) to decrease residual oil saturation and increasing the viscosity of the displacing fluid to improve overall sweep efficiency. IFT reduction allows better oil recovery by overcoming capillary effects, while the increased viscosity of the displacing fluid allows a more-homogeneous sweep of reservoir oil. Implementing chemical flooding in reservoirs with relatively high temperature and in-situ salinity (>200,000 ppm) is somewhat challenging. This paper describes the extensive laboratory work performed for the light-oil Raudhatain Lower Burgan (RALB) Reservoir (180°F/82°C) in Kuwait. Reservoir fluids were thoroughly characterized to preselect the most-suitable chemicals for the SP process. Reservoir crude oil was analyzed and recombined with gases (C1 through C3) depending on the reported gas/oil ratio (GOR) to reproduce the oil in place (OIP) at original reservoir conditions in terms of pressure, temperature, and oil composition. A shift of the live-oil equivalent alkane carbon number (EACN) was compared with the dead-oil EACN. Numerous surfactants were screened according to three main criteria: solubility in the envisioned injection brine, ultralow oil/water IFT, and chemical adsorption on reservoir rock. Different brine types were considered, and the use of adsorption inhibitors was also investigated. Furthermore, polymer screening involving temperature-resistant polymers was conducted by means of viscosity, long-term-aging, and adsorption tests. Polymer compatibility with the selected surfactants was also evaluated. The selected SP formulation was further evaluated through a series of coreflood experiments that were mainly dependent on chemical adsorption on reservoir rock and incremental oil recovery. An injection strategy was designed as a result of these experiments. Laboratory results obtained thus far are encouraging and provide a systematic methodology to design SP injection in high-temperature, high-salinity, and light-oil reservoirs that are similar to the RALB reservoir. Additional technoeconomic evaluation is in progress in preparation for field-scale deployment of SP injection at RALB Reservoir.

Low Salinity Water Flooding (LSWF), Can We Move Forward? The Economic Case

“…As our economic analysis showed even small projects can be very profitable. Examples of pilot studies (Windalia and Matzan fields) can be used as templates for the pilot design and pilot simulation applications (Al-Murayri et al 2018, Haynes et al 2013, Lüftenegger et al 2016). Based on the information from the field pilots and economic models, deployment plans are more likely to be executed if they are driven by the economic aspects.…”

Strategy for Optimum Chemical Enhanced Oil Recovery Field Operation

“…Also, the Winsor-based graphs was used as suggested for surfactantbased formulation development presented by (Al-Murayri et. al.2019a, Al-Murayri et al 2018a. Figure 2 shows an example of them.…”

“…In the previous section, we discussed the importance of the Winsor sensitivity graph for the evaluation of the surfactant formulation. We suggest an extended version of the Winsor graph reported by Al-Murayri et al 2018a where aqueous solubility map and static adsorption can be reported.…”

Nghiên cứu, đánh giá hiệu quả nâng cao thu hồi dầu bằng giải pháp bơm ép hệ hóa phẩm SP cho đối tượng Miocene dưới, vòm Nam mỏ Bạch Hổ

“…hệ số thu hồi tăng thêm 15% so với tổng trữ lượng dầu tại chỗ (original oil in place -OOIP). Đến nay, có nhiều mỏ trên thế giới áp dụng thành công bơm ép ASP (alkaline surfactant polymer) để nâng cao hệ số thu hồi dầu từ 15 -33% như ở mỏ Raudhatain [6], mỏ dầu nặng tại vịnh Bohai [7] , mỏ Algyő [8]… Mục tiêu quan trọng khi nghiên cứu, đánh giá khả năng ứng dụng giải pháp nâng cao hệ số thu hồi dầu là tính toán, xác định được hiệu quả kỹ thuật của giải pháp khi xem xét triển khai trên phạm vi toàn mỏ. Để đạt được mục tiêu này, ứng dụng mô hình mô phỏng khai thác mỏ là công cụ tối ưu nhất hiện nay.…”