Chemical EOR Economic Evaluation in a Low Oil Price Environment: Sabriyah Lower Burgan Reservoir Case Study

Abstract

Chemical EOR (CEOR) can be economic in a low-price environment, but it requires economic insights be integrated into the initial reservoir screening, laboratory and numerical simulation evaluations, and continued review through field implementation. The CEOR economic evaluation for the Sabriyah Lower Burgan (SALB) using this integrated process found that surfactant-polymer and alkaline-surfactant-polymer flood had different economic potentials due to different oil recoveries, facility costs, and operating costs. Initial reservoir screening of the SLAB indicated that LoSal and CO2, flooding might also have economic potential. Laboratory corefloods injecting field proportioned volumes of chemical solutions using dead oil and reservoir rock resulted in chemical cost average $3.12 per incremental barrel of oil for alkaline-surfactant-polymer formulations and $18.61 for surfactant-polymer formulations. Live oil corefloods for corresponding chemical formulations cost per incremental barrel estimates were $3.70 and $7.83. LoSal process provided no incremental oil based on laboratory coreflood results. Numerical simulation forecast economics included chemical costs, estimated operating costs, facilities cost, drilling of wells, and other capital costs. 2.2, 5.4, and 60 MMbbl pilots forecast by numerical simulation indicated that alkaline-surfactant-polymer cost per incremental barrel of oil was $28.63, $10.42, and $10.95 for the respective pilot sizes. Smaller pilots show a greater impact of fixed costs such a facilities and new wells. 5.4 and 60 MMbbl pilots paid out at 3.4 years or less. Corresponding discounted rates of return were up to 14%. Sensitivity analysis indicated that crude oil price has the greatest effect on chemical enhanced oil recovery economics, regardless of pilot size. This paper summarizes how economic applications at each phase of a chemical flood evaluation are performed and how those evaluations can be understood and applied to prevent adverse project selection. Economic parameters should be evaluated at various phases of project evaluation, influencing decisions to move forward. Methods of evaluation at each phase are documented and discussed using the Sabriyah, Lower Burgan study as a basis.

A Review on Wettability Alteration in Carbonate Rocks: Wettability Modifiers

“…By numerical simulation, the cost per barrel incremental oil for ASP application in Sabriyah Lower Burgan was obtained to be $28.63, $10.42, and $10.95 for pilot sizes of 2.2, 5.4, and 60 MMbbl, respectively. The corresponding rate of return was up to 14% …”

A Mechanistic Study of Wettability Alterations in Sandstone by Low Salinity Water Injection (LSWI) and CO2 Low Salinity Water-Alternating-Gas (WAG) Injection

“…However, this carbonic acid dissociates very rapidly at ambient conditions to bicarbonate [54], as shown in reaction (7). The bicarbonate electrolyte in the solution can also form 𝐶𝑂 as shown by reaction (8).…”

“…Another advantage for LSWI is that it can be combined with other EOR methods to further improve oil recovery [4][5][6]. According to economic evaluations on chemical EOR methods by Al-Murayri et al [7] and Muriel et al [8], LSWI and CO2 injection generate the highest net present value (NPV) and both methods are effective in increasing oil recovery. Therefore, a hybrid technique termed CO2 low salinity water-alternating-gas (LSWAG) injection, which combines the EOR effect of both methods, has been developed over the last 15 years.…”

Evaluation of the Oil Recovery Potential and Cost Implication Analysis of Alternative ASP Formulations for Sandstone and Carbonate Reservoirs

“…Estimation of the chemical cost of injected barrel of solution is performed in three steps. 32,42 First, the chemical cost per barrel injected is calculated using eq 4…”