MISCIBLE GAS INJECTION INTO OIL RESERVOIR IS COMMONEST METHOD TO ENHANCED OIL RECOVERY (EOR). KEY PARAMETER IN MISCIBLE DISPLACEMENT IS “ MINIMUM Miscibility PRESSURE”(MMP). ANALYTICAL CALCULATION IS ONE OF THE METHODS, WHICH DETERMINES THIS PARAMETER. THE ANALYTICAL THEORY OF ONE-DIMENSIONAL, DISPERSION-FREE DISPLACEMENT OF OIL BY INJECTION GAS WITH NC COMPONENTS HAS SHOWN THAT THE BEHAVIOR OF THE DISPLACEMENT IS COMPLETELY CONTROLLED BY A SEQUENCE OF KEY TIE LINES: THOSE THAT EXTEND THROUGH THE INITIAL OIL, INITIAL TIE LINE, AND INJECTION GAS COMPOSITIONS, INJECTION TIE LINE, AND NC-3 TIE LINES KNOWN AS CROSSOVER TIE LINES. THE THEORY ALSO DEMONSTRATES THAT IF ANY ONE OF THE KEY TIE LINES BECOMES A CRITICAL TIE LINE, THE DISPERSION-FREE DISPLACEMENT BECOMES PISTON-LIKE, AND MULTI-CONTACT Miscibility DEVELOPS. THEREFORE, THE MINIMUM Miscibility PRESSURE (MMP) IS CALCULATED AS THE LOWEST PRESSURE AT WHICH ANY ONE OF THE KEY TIE LINES BECOMES A CRITICAL TIE LINE. THIS PAPER CONTAINS RESULTS OF USING THIS METHOD FOR STUDY OF THE GEOMETRY OF THE KEY TIELINES IN TERNARY AND PSEUDO TERNARY SYSTEMS (INITIAL OIL AND INJECTION GAS TIELINES) AND MMP IS PRESENTED IN THIS DISSERTATION.

CARBON DIOXIDE FLOODING IS CONSIDERED TO BE ONE OF THE MOST EFFECTIVE ENHANCED OIL RECOVERY METHODS FOR THE LIGHT OIL RESERVOIRS. DEPENDING ON THE OPERATING PRESSURE, THE PROCESS MIGHT BE MISCIBLE OR IMMISCIBLE. MINIMUM Miscibility PRESSURE (MMP) IS THE MOST IMPORTANT PARAMETER FOR ASSESSING THE APPLICABILITY OF ANY MISCIBLE GAS FLOOD FOR AN OIL RESERVOIR. THE Miscibility CONDITION IS DETERMINED BY CONDUCTING DISPLACEMENT TESTS AT VARIOUS PRESSURES AND THE RECOVERY IS EXPECTED TO IMPROVE AS THE DISPLACEMENT PRESSURE INCREASES, AND STAYS ALMOST CONSTANT ABOVE THE MMP. IN THIS STUDY, MMP OF PURE CARBON DIOXIDE AND AN IRANIAN OIL RESERVOIR IS ESTIMATED USING SLIM-TUBE TEST. THE EXPERIMENT IS PERFORMED UNDER CONSTANT CO2 INJECTION RATE AND DIFFERENT DISPLACEMENT PRESSURES ABOVE THE BUBBLE POINT PRESSURE; INPUT AND OUTPUT PRESSURES ARE CONTINUALLY MONITORED DURING THE TEST; THE EFFLUENT LIQUID IS FLASHED TO ATMOSPHERIC CONDITIONS AND PRODUCED GASES ARE PASSED THROUGH GAS CHROMATOGRAPHY FOR COMPOSITIONAL ANALYSIS. VOLUMETRIC OIL RECOVERY IS MEASURED. OIL RECOVERY IS PLOTTED AGAINST THE INJECTION PRESSURE AT 1.2 PORE VOLUME OF INJECTED FLUID. THE RESULTS SHOW THAT THE OIL RECOVERY IS MORE THAN 90% OF ORIGINAL OIL IN PLACE FOR ALL PRESSURES WITH A CONSTANT SLOPE ABOVE THE BUBBLE POINT PRESSURE. THEREFORE, MMP IS CONSIDERED TO BE EQUAL TO THE BUBBLE POINT PRESSURE. IN ADDITION TO THE PLOT OF OIL RECOVERY VERSUS PRESSURE, Miscibility IS ALSO CONFIRMED BY THE EFFLUENT GAS COMPOSITION, SLIM-TUBE PRESSURE DROP AND VISUAL OBSERVATIONS OF PHASE BEHAVIOR. SINGLE PHASE HIGH PRESSURE FLUID AT THE OUTLET OF SLIM-TUBE, SMALL PRESSURE DROP ACROSS IT AND NO METHANE BANK IN THE COMPOSITION OF EFFLUENT GAS, ALL INDICATE THAT THE Miscibility IS COMPLETELY ACHIEVED. THE EXPERIMENTAL RESULTS ARE VALIDATED BY MODELING THE TEST USING FULLY COMPOSITIONAL SIMULATOR. THE EFFECT OF VARYING CO2 MOLE FRACTION IN INJECTED FLUID IS INVESTIGATED. THE RESULTS SHOW THAT AN INCREASE IN CO2 MOLE FRACTION IN INJECTED GAS DECREASES MMP SIGNIFICANTLY.

THE RHEOLOGICAL, THERMAL AND DYNAMIC MECHANICAL PROPERTIES OF BINARY BLENDS OF AN ISOTACTIC POLYPROPYLENE (PP) AND ETHYLENE/VINYL ACETATE COPOLYMER (EVA) CONTAINING 18 WT. % OF VA AT VARYING BLENDING RATIOS WERE INVESTIGATED AND COMPARED WITH THOSE OF THE PURE COMPONENTS. USING DIFFERENT METHODS Miscibility OF THE BLENDS WAS STUDIED. IT WAS FOUND THAT Miscibility OF BLENDS INCREASES AT AROUND 60 WT.% OF EVA LOADING. BESIDES, SOME OTHER ASPECTS OF BLENDS LIKE MELTING BEHAVIOR AND DAMPING PROPERTIES WERE INVESTIGATED. IN THE CASE OF DAMPING PROPERTIES PRESENCE OF THREE DISTINCT DAMPING BEHAVIORS CORRESPONDING TO THREE DIFFERENT MORPHOLOGIES WERE SHOWN.

IN ORDER TO CREATE AN INTEGRATED SIMULATION MODEL, IT IS ESSENTIAL TO HAVE A FLUID CHARACTERIZATION BASED ON REVISION AND VALIDATION OF THE AVAILABLE LABORATORY DATA. THESE INCLUDE PVT STUDIES, PRODUCTION DATA, RFT LOGS, ETC. IN CASE OF EOR PROCESS MODELING, IT IS NECESSARY TO ALSO CONSIDER THE SPECIAL FLUID TESTS (SWELLING TEST AND DISPLACEMENT MEASURES ON CORES) WHICH PERMIT THE EVALUATION OF THE INJECTED GAS EFFECT ON THE ORIGINAL FLUID PROPERTIES IN THE RESERVOIR, PARTICULARLY AT THE SATURATION PRESSURE.THE THERMODYNAMIC STUDY BASED ON THE AVAILABLE EXPERIMENTAL PVT DATA, TAKEN FROM THREE APPRAISAL WELLS OF A CARBONATE OIL FIELD IS PRESENTED. THE FLUID SYSTEM FLOWING THROUGHOUT TWO RESERVOIR LEVELS IS CHARACTERIZED BY MEANS OF EQUATIONS OF STATE FINALISED TO A FULL 3D GAS INJECTION RESERVOIR STUDY. THE OBJECTIVE IS OPTIMIZING THE FIELD PRODUCTION STRATEGIES CONSIDERING THE INJECTION OF NATURAL GAS.OVERVIEW OF ALL THE EXPERIMENTAL DATA SHOWS A GOOD AGREEMENT AMONG THE TESTS PERFORMED ON SAMPLES BELONGING TO THE SAME LEVEL. IN THIS STUDY TWO EQUATIONS OF STATE (THREE PARAMETERS PENG-ROBINSON EQUATION) HAVE BEEN CALIBRATED FOR THE TWO LEVELS. THE SIMULATED PVT PARAMETERS BY THE TUNED EOS FOR THE TWO FLUIDS SAMPLES ARE IN GOOD AGREEMENT WITH THE ALREADY MEASURED EXPERIMENTAL DATA. IN ADDITION, THE SWELLING TEST SIMULATION SHOWS A FAIR MATCH WITHIN LIMITS OF CUBIC EOS.THE SLIM TUBE EXPERIMENTS PERFORMED BY OILPHASE LABORATORY TO STATE THE Miscibility /IMMiscibility CONDITION OF THE RESERVOIR OIL WITH RESPECT TO THE GAS EXTRACTED AT THE SEPARATORS ARE ALSO SIMULATED. CONSEQUENTLY THE SENSITIVITY OF THE Miscibility CONDITIONS TO POSSIBLE VARIATIONS OF THE COMPOSITION OF THE INJECTED GAS IS INVESTIGATED.

Miscibility OF POLYVINYLCHLORIDE/ POLYCAPROLACTONE (PVC/PCL) BLEND HAS BEEN STUDIED BY DILUTE SOLUTION VISCOMETRY (DSV) METHOD. VARIOUS Miscibility CRITERIA WERE USED TO DETERMINE POLYMERPOLYMER Miscibility IN TETRAHYDROFURAN (THF) SOLUTION. ...