REMAINING OIL IN THE RESERVOIR CAN BE DIVIDED INTO TWO CLASSES, FIRSTLY RESIDUAL OIL TO THE WATER FLOOD AND SECONDLY OIL BYPASSED BY THE WATER FLOOD. RESIDUAL OIL MAINLY CONTAINS CAPILLARY TRAPPED OIL. WATER FLOODING ONLY IS NOT ABLE TO PRODUCE CAPILLARY TRAPPED OIL SO THAT THERE IS A NEED FOR ADDITIONAL TECHNIQUE AND FORCE TO PRODUCE AS MUCH AS RESIDUAL OIL. ONE WAY OF RECOVERING THIS CAPILLARY TRAPPED OIL IS BY ADDING CHEMICALS SUCH AS ALKALINE, SURFACTANT AND POLYMER TO THE INJECTED WATER. THIS ARTICLE PRESENTS DIFFERENT ASPECTS OF SAP COMBINATION FLOODING AND DISCUSSES ABOUT ONE REAL CASE WHICH SAP PROCESS SUCCESSFULLY HAVE BEEN DONE. THE CRUCIAL ROLE OF ALKALI IN AN ALKALINE SURFACTANT PROCESS IS TO REDUCE ADSORPTION OF SURFACTANT DURING DISPLACEMENT THROUGH THE FORMATION. ALSO ALKALI IS BENEFICIAL FOR REDUCTION OF OIL-WATER IFT BY IN SITU GENERATION OF SOAP, WHICH IS AN ANIONIC SURFACTANT. GENERALLY ALKALI IS INJECTED WITH SURFACTANT TOGETHER. SURFACTANTS ARE CONSIDERED FOR ENHANCED OIL RECOVERY BY REDUCTION OF OIL–WATER INTERFACIAL TENSION (IFT). ON THE OTHER HAND, POLYMER IS VERY EFFECTIVE ADDITION BY INCREASING WATER VISCOSITY WHICH CONTROLS WATER MOBILITY THUS IMPROVING THE SWEEP EFFICIENCY. SAP COMBINATION FLOODING TO ENHANCE OIL RECOVERY IS EFFECTIVE AND ECONOMIC, IT CAN INCREASE OIL RECOVERY RATE BY ABOUT 20% (OOIP) FOR MANY YEARS. CRUDE OIL CHARACTERISTICS, BRINE CHARACTERISTICS, BOTTOM-HOLE TEMPERATURE, ALKALI, WELL HISTORY, AND TREATMENT DESIGN ARE CONSIDERED TO MAXIMIZE THE TREATMENT RESULTS.

IN THIS PAPER, WE PERFORM DYNAMIC IMBIBITION SIMULATIONS ON A LARGE SCALE HETEROGENEOUS FRACTURED BLOCK. THE PURPOSE IS TO SEEK OPTIMUM CONDITIONS UNDER WHICH MAXIMUM OIL CAN BE RECOVERED IN LARGE-SCALE EXTREMELY-HETEROGENEOUS RESERVOIRS. IN THIS PAPER, WE ONLY CONSIDER HORIZONTAL WELLS. HOWEVER, WE SIMULATE BOTH CONTINUOUS AND SLUG INJECTION SCENARIOS. VARIOUS CHEMICAL SOLUTIONS ARE INJECTED. THESE INCLUDE: WATER, POLYMER, SURFACTANT, ALKALI, AND DIFFERENT COMBINATIONS OF THEM. FOR CONVENIENCE OF SIMULATION, ALTHOUGH THIS IS NOT PHYSICALLY CORRECT, ALKALI REPRESENTS THE WETTABILITY MODIFYING AGENT, WHILE THE SURFACTANT IS THE AGENT THAT LOWERS THE IFT TO ULTRA-LOW VALUES. THEREFORE, A SIMULATION LABELED AS INDICATES THAT THE INJECTED CHEMICAL SOLUTION LOWERS THE IFT TO ULTRA LOW VALUES AS WELL AS ALTERS THE WETTABILITY FROM MIXED-WET TO WATER-WET. ON THE OTHER HAND, A SIMULATION LABELED ASP DOES THE ABOVE TASK AS WELL AS MAKING THE CHEMICAL SOLUTION VISCOUS (POLYMER). THE RECOVERY CURVES ARE COMPARED AND APPROPRIATE PROFILES ARE DEMONSTRATED IN ORDER TO UNDERSTAND THE RESULTS.

IN THIS PAPER WE PERFORM DYNAMIC IMBIBITION SIMULATIONS ON A LARGE SCALE HOMOGENOUS FRACTURED BLOCK. THE PURPOSE IS TO SEEK OPTIMUM CONDITIONS UNDER WHICH THE OIL RECOVERY IS MAXIMAL IN A LARGER SCALE MODEL. IN ORDER TO DO THIS, WE CONSIDER 7 DIFFERENT CASES WITH VARYING RELATIVE IMPORTANCE OF CAPILLARITY AND VISCOUS FORCES. THE INJECTIONS ARE ALL CONTINUOUS. VARIOUS CHEMICAL SOLUTIONS ARE INJECTED. THESE INCLUDE: WATER, POLYMER, SURFACTANT, ALKALI, AND DIFFERENT COMBINATIONS OF THEM. FOR CONVENIENCE OF SIMULATION, EVEN THOUGH THIS IS NOT PHYSICALLY CORRECT, ALKALI REPRESENTS THE WETTABILITY MODIFYING AGENT, WHILE THE SURFACTANT IS THE AGENT THAT LOWERS THE IFT TO ULTRA LOW VALUES. THEREFORE, A SIMULATION LABELED AS INDICATES THAT THE INJECTED CHEMICAL SOLUTION LOWERS THE IFT TO ULTRA LOW VALUES AS WELL AS ALTERS THE WETTABILITY FROM MIXED-WET TO WATER-WET. ON THE OTHER HAND, A SIMULATION LABELED ASP DOES THE ABOVE TASK AS WELL AS MAKING THE CHEMICAL SOLUTION VISCOUS (POLYMER). THE RECOVERY CURVES ARE COMPARED FOR EACH CASE NUMBER AND APPROPRIATE PROFILES ARE DEMONSTRATED IN ORDER TO UNDERSTAND THE RESULTS.

IN THIS PAPER, WE SIMULATE DYNAMIC IMBIBITION ON A SMALL SCALE HOMOGENOUS FRACTURED BLOCK. THE PURPOSE IS TO SEEK OPTIMUM CONDITIONS UNDER WHICH THE OIL RECOVERY IS MAXIMAL.IN ORDER TO DO THIS, WE CONSIDER A BASE CASE SIMULATION AND THEN WE DOSENSITIVITY ANALYSES ON SEVERAL PARAMETERS. THE INJECTIONS ARE ALL CONTINUOUS. VARIOUS CHEMICAL SOLUTIONS ARE INJECTED. THESE INCLUDE: WATER, POLYMER, SURFACTANT, ALKALI, AND DIFFERENT COMBINATIONS OF THEM. FOR CONVENIENCE OF SIMULATION, ALTHOUGH THIS IS NOT PHYSICALLY CORRECT, ALKALI REPRESENTS THE WETTABILITY MODIFYING AGENT, WHILE THE SURFACTANT IS THE AGENT THAT LOWERS THE IFT TO ULTRA-LOW VALUES. THEREFORE, A SIMULATION LABELED AS INDICATES THAT THE INJECTED CHEMICAL SOLUTION LOWERS THE IFT TO ULTRA LOW VALUES AS WELL AS ALTERS THE WETTABILITY FROM MIXED-WET TO WATER-WET. ON THE OTHER HAND, A SIMULATION LABELED ASP DOES THE ABOVE TASK AS WELL AS MAKING THE CHEMICAL SOLUTION VISCOUS (POLYMER). THE RECOVERY CURVES ARE COMPARED FOR EACH SENSITIVITY ANALYSIS AND APPROPRIATE PROFILES ARE DEMONSTRATED IN ORDER TO UNDERSTAND THE RESULTS.