Summary Capillary imbibition tests are commonly applied to measure wettability-alteration potential of chemicals. However, these tests are exhaustive, time-consuming, and expensive, and the underlying physics of the alteration process from a surface-chemistry point of view is often limited and/or unexplained. Contact-angle measurement is a quicker and more-feasible screening tool to assess the emerging wettability modifiers. It also provides visual data on the mechanics of the wettability-alteration process. This paper focuses on contact-angle measurements as a means to evaluate the wettability alteration on mineral plates and porous-rock samples. Imidazolium ionic liquids were tested at different concentrations. To study the effect of pH on the wettability, sodium chloride and sodium borate were used at different concentrations. The composition of divalent ions was varied because of their possible use with low-/high-salinity water as wettability-alteration agents. Unmodified and surface-modified silica, zirconium, and alumina nanoparticles were also tested. Contact-angle measurements were performed initially on mica, marble, and calcite plates. Experiments were repeated on polished surfaces of Berea sandstone, Indiana limestone, and cleaned Grosmont carbonate cores. Oils (pure and solvent-mixed crude oils) with different viscosities and densities were used to test the effect of oil type on the process. The images were obtained by an single-lens reflex (SLR) camera at different temperatures ranging from 25 to 80°C. By testing with different concentrations, the optimum chemicals were found for different mineral-plate/porous-rock systems. Then, the results were cross checked with the imbibition tests performed on the same samples to validate the contact-angle-measurement observations. Thermal-stability tests were also performed in case of their use during or after a thermal method. For the thermal-stability tests, contact-angle experiments were conducted in a high-pressure and high-temperature (up to 200°C) cell. It was shown that certain ionic liquids and nanofluids are stable at high temperatures and can be efficiently used at low concentrations.

Capillary imbibition tests are commonly applied to measure wettability alteration potential of chemicals. However, these tests are exhaustive, time-consuming, expensive, and the underlying physics of the alteration process from a surface chemistry point of view is often limited and/or unexplained. Contact angle measurement is a quicker and more feasible screening tool to assess the emerging wettability modifiers. They also provide visual data on the mechanics of the wettability alteration process. This paper focuses on contact angle measurements as a mean to evaluate the wettability alteration on mineral plates and porous rock samples. Imidazolium ionic liquids were tested at different concentrations. To study the effect of pH on the wettability, sodium chloride and sodium borate were used at different concentrations. The composition of divalent ions was varied due to their possible use with low/high salinity water as wettability alteration agent. Unmodified and surface modified silica, zirconium, and alumina nanoparticles were also tested. Contact angle measurements were performed initially on mica, marble, and calcite plates. Experiments were repeated on polished surfaces of Berea sandstone, Indiana limestone, and -cleaned- Grosmont carbonate cores. Oils (pure and solvent mixed crude oils) with different viscosities and densities were used to test the effect of oil type on the process. The images were obtained by an SLR camera at different temperatures ranging from 25 to 80°C. By testing with different concentrations, the optimum chemicals were found for different mineral plates/porous rock systems. Then, the results were cross-checked with the imbibition tests performed on the same samples to validate the contact angle measurement observations. Thermal stability tests were also performed in case of their use during or after a thermal method. For the thermal stability tests, contact angle experiments were conducted in a high pressure and high temperature (up to 200°C) cell. It was shown that certain ionic liquids and nanofluids are stable at high temperatures and can be efficiently used at low concentrations.

Application of primary and secondary recovery processes in naturally fractured carbonate reservoirs containing heavy-oil/bitumen usually results in no or low recovery. Hence, an enhanced oil recovery (EOR) method is typically needed at early stages. Changing the characteristics of rock/fluid system, such as wettability and interfacial tension, in such challenging reservoirs becomes critically essential in this attempt. Recovery from the Grosmont carbonate unit is further complicated by the immobility of bitumen as well as extreme reservoir heterogeneity. This specific reservoir requires either pre-heating or solvent dilution before any further EOR attempts.This study investigates the applicability of the modified version of the previously proposed SOS-FR (steam-over-solvent injection in fractured reservoirs) method to recover bitumen from the Grosmont carbonate unit. Using the suggested methodology, three phases were applied on a total of 13 preserved core samples from this unit. In Phase-1, the cores taken from three different formations of the Grosmont unit were soaked into a liquid solvent (heptane or distillate) at ambient conditions. Depending on the quality of the bitumen, a certain amount of recovery was obtained. The original form of the SOS-FR method was based on steam (or hot-water) injection at the temperature near the boiling point of the solvent as the following phase to retrieve the solvent. In Phase-2, instead of this "thermodynamic" approach, we tested an "interfacial" approach and soaked the samples into water with chemicals additions. Wettability modifiers tested include high pH solution, surfactants and ionic liquids, which were screened in our earlier work (SPE 170034) and selected as the most useful wettability alteration chemicals for oil-wet carbonates. One of the key benefits of the ionic liquids is that they are environmentally friendly and can be customized for particular rock/fluid system while pH solutions are economically attractive. Phase-2 was applied at room temperature and at 65°C. Finally, Phase-3 was applied by increasing temperature to the bubble point of the solvent to mimic hot-water injection with chemicals.Each phase was analyzed in terms of ultimate oil recovery (and wettability alteration), time to reach this amount, the most suitable wettability alteration chemicals, and soaking times needed. The results revealed that the solvent phase not only affects the bitumen properties, but also changes Grosmont rock characteristics significantly. Wettability alteration of the fractured Grosmont reservoir was observed to be highly critical, not only for additional oil recovery but also for solvent retrieval. Specific high pH solution was observed to efficiently alter wettability and recover considerable amount of bitumen/solvent mixture fairly quick showing a potential as a low cost chemical to recover bitumen. The results and discussion on the optimization of the process in terms of the solvent soaking period, wettability alteration chemicals, and the effect of temperature will be...

Abstract:In the present study, the structural properties which included the X-rays diffraction, and DSC, the mechanical properties, which include tensile test, threepoint bending test (Bending Test), hardness test and thermal conductivity of the polymers reinforced with calcite (PVC/CaCO 3 ) at different temperature (25-40-80-120-160-200-220) °C. The research results showed that the X C degree of X-ray diffraction decreased at high temperatures (220 ˚C), while the inter-polymerized polymer (PVC / CaCO 3 ) increased at high temperatures. The DSC test results showed that the degree of crystallinity (X C ) decreases at high temperatures (220 ˚C). The mechanical test results, their values were found to decrease at (220 ˚C) higher temperatures. Finally, the obtained results were indicated that the thermal conductivity values decrease at (220 ˚C). Keywords IntroductionPolyvinyl chloride PVC is one of the most commonly used man-made polymers because of the unrivalled combination of properties that it offers. It is the ratio of economic cost to performance makes it immediately more accessible than most other materials and the diversity of ways in which it

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