Determination of the best-fit multiphase flow correlation for high water-cut wells using prosper

Pressure drop in a vertical or deviated borehole is mainly due to hydrostatic changes and friction when the produced fluids flow to the surface. When the oil is flowing upwards, the flowing pressure along the tubing string will drop and gas starts to liberate from the oil. Thus, multiphase flow forms in the tubing string. Hence, adequate modeling of vertical lift performance is required to predict the pressure drop and subsequently the wellbore pressure. The bottomhole pressure prediction was realized by using PROSPER, a program developed by Petroleum Experts. The data of oilwell X-01 with high water cut (i.e., 56%) in field X was used in this research work. The most accurate correlation was chosen from 12 selected built-in correlations to predict the pressure drop via gradient matching. A sensitivity analysis has been done to observe the parameters that affected the vertical lift performance of a high water cut well. These parameters were tubing diameter, gas-oil ratio, wellhead pressure, water cut, and tubing roughness. The results show that Dun and Ros original correlation appeared to be the best-fit correlation for well X-01. Results from sensitivity analysis indicated that reduction of wellhead pressure from 390 psi to 285.3 psi could increase liquid rate by 13.2%. An adjustment of wellhead pressure gave the most significant impact on the production rate of well X-01 as compared to other four parameters studied

Fluid loss mitigation via multi-wall carbon nanotubes-enriched water-based drilling fluid

Fluid loss is a common drilling problem that should be addressed immediately to prevent formation damage. The most efficient and easiest way to overcome fluid loss is by adding fluid loss control additives in drilling mud as fluid loss control additives can temporarily plug pores in the formations. In this study, combination of durian rind (DR) and multi-wall carbon nanotubes (MWCNT) was studied to increase the effectiveness of fluid loss control due to fibrous nature of DR and complex structure of MWCNT. This can reduce the durian waste and also the cost of fluid loss additives (FLAs). The objective of this study was to study the effect of MWCNT in Hydro-Pac R, a commercial fluid loss control additive and DR to control fluid loss in water-based mud by comparing the rheological and fluid loss properties at different concentrations of durian rind and carbon nanotubes at room condition and after aging. The performance of the fluid loss control additives was also tested in high temperature and high pressure conditions. Fine DR and Hydro-Pac R were tested using five concentrations varied from 0.6 to 1.0 ppb in water-based mud. The mud weight of those mud samples were maintained at 10 ppg. Rheological tests were carried out to determine the plastic viscosity, gel strength, and yield point while fluid loss test was to determine the volume of fluid loss under 100 psi of differential pressure and the mud cake thickness. Then the best concentration for each FLA from the fluid loss test was mixed with MWCNT of concentrations from 0.02 to 0.1 lb/bbl and repeated the rheological test and further investigated the fluid loss performance of the mixture in high pressure, high temperature condition. Overall, the fluid loss results indicated that the performance of drilling fluids with the presence of commercial additive, Hydro-Pac R was better than durian rind. The mixture of Hydro-Pac R with MWCNT produced better fluid loss control in low pressure low temperature (LPLT) filter press and high pressure and high pressure (HPHT) before and after aging process than DR with MWCNT

Wettability alteration of dolomite rock using nanofluids for enhanced oil recovery

Wettability alteration of rock by surfactant has been considered as feasible method for recovery of oil reservoirs by modifying the wettability of rock surface from oil-wet to water-wet condition. The impact of surfactant can be enhanced by adding nanoparticles. Cationic surfactant performed well in carbonate rock by forming ion pairs between cationic head and acidic component of the crude. Meanwhile, nanoparticles will form continuous wedge film between the liquid and solid surface. In this paper, Al2O3 and ZrO2 nanoparticles were used as enhanced oil recovery (EOR) agents. The impact of these two nanoparticles on contact angle and interfacial tension was studied. Besides that, adsorption Cetyltrimethylammonium Bromide (CTAB) surfactant on rock surface was also investigated. The results show a significant change in water-oil contact angle after application of surfactant and nanoparticles. Initial water-oil contact angle for 6 slides demonstrate oil-wet condition. Then, the slides were submerged in prepared solution for 48 hours. The result shows that, slides 2, 5 and 6 changes drastically to more water-wet condition with contact angle 56°, 40° and 47° respectively. For surfactant adsorption, the adsorption is very fast at the beginning. The adsorption rate after 5 minutes was 50 mg/g and after 60 minutes the adsorption rate was 310 mg/g. The adsorption rate slowed down after 60 minutes and after 180 minutes the adsorption rate was 315 mg/g in which the rate of adsorption achieve equilibrium. Nanoparticles retention test and Zeta potential shows that Al2O3 is more stable than ZrO2. The results for interfacial tension (IFT) also show a significant reduction. The IFT value reduces from 8.46 mN/m to 1.65 mN/m and 1.85 mN/m after the application of Al2O3 and ZrO2 nanofluids respectivel

Evaluation of kapok fiber and gypsum mixture to improve fire resistance

Fire can be formed when these three elements, hot, oxygen, and combustible materials, are present. It produces heat and light through a chemical process of oxidation reactions that occur rapidly. It is widely known that a human's life on the earth cannot be separated from the fire. But we often hear a phrase about the fire: 'friendly when it is small, deadly when it is big'. Based on this expression, we can say that the fire is not only furnishing benefits to humans but it also can destroy property and killed many lives each year. Therefore, a fire protection should be given priority in our daily life, especially the use of fire resistant doors in commercial and office buildings. Kapok, a natural fiber, which has a low thermal conductivity has been selected and examined in this study as a fire-resistance material. The objective of this study was to find the resistance of gypsum when mixed with kapok fiber. The laboratory works involved the preparation and testing of composite samples of gypsum and kapok fiber, which were prepared with different thicknesses, namely 6.4mm, 9.5mm, and 12.7mm. Then composite samples of three different compositions, namely 1000g of gypsum: 10g of kapok, 1000g of gypsum: 20g of kapok, and 1000g of gypsum: 30g of kapok were prepared for each of those thicknesses. All the composite samples were burnt, in accordance to MS 1073 (1996), in a combustion chamber that had been designed and fabricated in Combustion Laboratory, Faculty of Mechanical Engineering. The experimental results revealed that the composite sample of 12.7 mm thickness gave the highest fire resistance for all the prescribed compositions while the composite sample of 30 g of kapok fiber produced the highest fire resistance compared to other two compositions. In short, a composite mixture of gypsum and kapok fiber has the potential to be used as a fire-resistance material in manufacturing of fire resistant doors, walls, and ceilings for the building construction sector