In the Kutei, Indonesia oil and gas producing basin, a serious flow assurance problem has occurred in the form of an oil-water emulsion. This emulsion, formed via the reaction of carboxylic acids in oil with sodium-chloride-bicarbonate-acetate produced water, is difficult to break. At the West Seno deepwater field, the floating production unit (FPU), utilizes heat and an acidic demulsifier to break the emulsion into salable oil and water suitable for overboard discharge. Over the past couple of years, a few wells have begun to produce an emulsion that is not easily broken by the FPU heat/acid demulsifier process. Characterization studies of the new emulsion show that it is very different chemically from the common sodium soap emulsions produced at West Seno field since production inception in 2003. The former contains primarily sodium alkyl benzoates, while the latter consists primarily of sodium n-alkanoates ranging from C10 -C36. Oil produced from the wells that produce the new "difficult" emulsion is waxier than normal. The combination of waxes and the alkyl benzoic acids is apparently responsible for the formation of the "difficult-to-treat" emulsion.Laboratory screening tests of new sodium soap emulsion inhibitors have shown that heat and several non-acid inhibitors break the emulsions more efficiently than the incumbent acid demulsifier. One new inhibitor was especially efficient and more cost effective than all other inhibitors included in the study. Not only is this new inhibitor more effective at a lower dosage, but its bulk price is also less. This inhibitor was injected into two West Seno wells that produce the "difficult" emulsion in a short field trial. Coupled with reservoir heat, the inhibitor successfully broke the emulsion at a reasonable dosage. The chemical appears to inhibit sodium alkyl benzoates and sodium n-alkanoates via a complexation mechanism. We are now preparing for commercial deployment of the new inhibitor in West Seno wells. We believe that the new inhibitor will eliminate or reduce the need to treat fluids on the FPU with the incumbent acidic demulsifier, which should reduce corrosion and by-product scaling caused by the incumbent.

One of the most serious flow assurance challenges encountered during oil and gas production is the deposition of paraffins on formation surfaces, flowlines, as well as on other processing equipment. Paraffin deposition can cause problems in the production system that includes blocked pipelines, lower production rates, solids-accumulation, and increased remediation time and costs. Several thermal, mechanical, and chemical methods are used to mitigate these challenges, and, of the chemical techniques available, paraffin inhibitors are deployed to mitigate the deposition problem. Several classes of polymers have been developed into paraffin inhibitors to delay the onset of paraffin precipitation and alter the crystal morphology of the precipitated paraffin particles – these combined phenomena reduce the extent of deposition. While these polymers control wax deposition, several challenges remain for their use in both cold and deep-water environments. Many of these polymers exhibit reduced solubility in common solvents used to formulate treatment products, and, as a consequence can only be blended at low concentrations for use in harsh environments. A real demand exists for new paraffin inhibitors that have enhanced formulation-stability at much higher concentrations suitable for use under low-temperature and high pressure environmental conditions. This paper describes the developmental work and performance evaluation of a novel series of polymers specifically developed for use in low-temperature environments.

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In the Kutei, Indonesia oil and gas producing basin, a serious flow assurance problem has occurred in the form of an oil-water emulsion. This emulsion, formed via the reaction of carboxylic acids in oil with sodium-chloride-bicarbonate-acetate produced water, is difficult to break. At the West Seno deepwater field, the floating production unit (FPU), utilizes heat and an acidic demulsifier to break the emulsion into salable oil and water suitable for overboard discharge. Over the past couple of years, a few wells have begun to produce an emulsion that is not easily broken by the FPU heat/acid demulsifier process. Characterization studies of the new emulsion show that it is very different chemically from the common sodium soap emulsions produced at West Seno field since production inception in 2003. The former contains primarily sodium alkyl benzoates, while the latter consists primarily of sodium n-alkanoates ranging from C10 -C36. Oil produced from the wells that produce the new "difficult" emulsion is waxier than normal. The combination of waxes and the alkyl benzoic acids is apparently responsible for the formation of the "difficult-to-treat" emulsion.Laboratory screening tests of new sodium soap emulsion inhibitors have shown that heat and several non-acid inhibitors break the emulsions more efficiently than the incumbent acid demulsifier. One new inhibitor was especially efficient and more cost effective than all other inhibitors included in the study. Not only is this new inhibitor more effective at a lower dosage, but its bulk price is also less. This inhibitor was injected into two West Seno wells that produce the "difficult" emulsion in a short field trial. Coupled with reservoir heat, the inhibitor successfully broke the emulsion at a reasonable dosage. The chemical appears to inhibit sodium alkyl benzoates and sodium n-alkanoates via a complexation mechanism. We are now preparing for commercial deployment of the new inhibitor in West Seno wells. We believe that the new inhibitor will eliminate or reduce the need to treat fluids on the FPU with the incumbent acidic demulsifier, which should reduce corrosion and by-product scaling caused by the incumbent.

No abstract