Alkaline Surfactant Polymer Formulation for Saudi Arabian Carbonate Reservoirs

Abstract

This paperwas pn?fmred for rescntition x the 1996 SPE/DOE Tenth~~u tn on Intprcwut Ji~Recovery, TUIS., OK, ZI-X April This paper wa8 selected for presentation by the S PE Program Committee followin review of infonrmtion contained in an abstract 1! submitted by the au or(s). Conkns of tbe pa~r. as presc.mui, have not b-scn reviewed by the Satiety of Petroleum En in.x.r$ and are subject to correction by the q uthor(s), Thc mstcna , q s rcxntcd, j &ktml dacs ttcx ttect%sm'ity re.ftect mty position of the Societ of Engineers or iu members. Papers prcsxtlcd at SP mcc:mgs are subjest to publication rsview by an Editorial Committee of the Scmety of Petroleum En@mcem. Permissim to copy is restricted to an akrset of not more than 300 words. Ittustmtions may not be copied. The abstract shoutd contain conspicuous qcknowlcdemcmt of where and by whom the pqxr was r.&tcd, Wrikz Libra%n, SPE, P. O. Box 8333836. Kichadvm. %X 75083.3836 U.S. A.. fax 01-214-952-9435. Abstract This paper presents a systematic study to test the applicability of alkaline-surfactant-poly mer (ASp) processes as an enhanced oil recovery method to Saudi Arabian carbonate reservoirs, with the objective of designing a cost-effeetive ASP slug. To achieve this objec~ive, several alkalis were first screened to lest [heir compatibility with the injected sea water that has large quantities of divalent ions. Then surfactant-poly mer, alkalis-surf actant, and alkali s-surfactant-po lymer interactions at the reservoir temperature (90°C) were investigated, Static and dynamic adsorption of surfactant on reservoir carbonate rocks were also investigated at the same temperature. IFT measurements were also made between the slugs formulated and crude oil from the same reservoir. And finally core flooding tests were carried out using Arab-D carbonate core samples to test References and illustrations at end of paper the effectiveness of the formulated slugs. Two surfactants were used, Triton X-102 and Ethoxylated sulfonate (Dodi-flood B 1083), and the plymer used WSS FLOCON 4800C. The results of the compatibility tests showed that the ASP slug has to be prepared using a softened brine and be protected by pre-and after-flush softening brine slugs. B 1083 surfactant was found to be a promising candidate surfactan[ for the conditions of the Saudi Arabian carbonate reservoir. A combination of NaHC03 and Na2C03 was found to significantly reduee the adsorption level of B 1083 surfactant on carbonate rock at low surfactant concentrations (<1 YO by wt.). This is very desirable for formulation of a costcffective ASP slug. Finally, the results of core flooding tests under reservoir conditions using the formulated ASP slugs on Arab-D carbonale core samples showed a promising additional oil recovery. Alkaline Surfactant Polymer Formulation for Saudi Arabian Carbonate Reservoirs SPE No. 35353 understood. This is because of the high dependence of this process on reaetions among the injected fluid and minerals on the surface of the reservoir rocks, which are not chemically inert, and the...

Enhanced Oil Recovery: An Update Review

“…As of date, no chemical flooding other than polymer-flooding field in carbonate reservoirs have been reported in the literature reviewed. However, ASP has been tested in carbonate formations in the lab in Arab-D [193] and Upper Edward's [19] and Pietra Leccese outcrop [194][195][196] in core samples. Alkali-Surfactant single well test has been reported in the Mauddud carbonate reservoir in Bahrain as part of ASP feasibility studies in oil-wet limestone reservoirs [197].…”

Main Controlling Factor of Polymer-Surfactant Flooding to Improve Recovery in Heterogeneous Reservoir

“…Emulsification is a common phenomenon in the SP flooding and also an important mechanism for EOR [9,14,19]. In order to evaluate the efficiency of chemical emulsifying the oil, a series of emulsification experiments are conducted, according to the description of the experimental method in Section 2.4.…”

“…The alkali-surfactant-polymer (ASP) system can reduce both the mobility ratio and the IFT, so it can effectively reduce the remaining oil saturation [6][7][8]. The alkali in ASP system can react with the organic acid in the oil to generate surfactant [9]. As a result, the IFT can be reduced to a larger extent due to the synergy between surfactant added and generated.…”

Characterization of Mixed Wettability at Different Scales and Its Impact on Oil Recovery Efficiency

“…• Adsorption of anionic surfactants is low with the addition of an alkali, especially with sodium carbonate 23,[41][42][43] ;…”