Issham Ismail

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 dolomites demonstrate oil-wet condition. Then, the dolomites were submerged in prepared solution for 48 hours. The result shows that, dolomites 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 respectively

Nanoparticles Performance as Fluid Loss Additives in Water Based Drilling Fluids

Nanoparticles are used to study the rheological characteristics of drilling fluids. Nanoparticles have high surface to volume ratio, therefore only small quantity is required to blend in the drilling fluid. This research evaluates the performance of nanosilica and multi walled carbon nanotubes (MWCNT) as fluid loss additives in water based drilling fluid with various nanoparticles concentration and temperature. The results show that plastic viscosity, yield point and gel strength of drilling fluid increases as the concentration of nanoparticles increased. Drilling fluid with nanosilica gives the highest filtrate loss of 12 ml and mudcake thickness of 10 inch at 1 g concentration at 300°F. However, drilling fluid with MWCNT shows a decreasing trend in fluid loss and mudcake thickness. The results also show that xanthan gum containing 1 g of MWCNT gives 4.9 ml fluid loss and mudcake thickness of 4 inch at 200°F. After aging, plastic viscosity, yield point and gel strength of mud containing nanoparticles decrease significantly especially for 1 g of nanosilica and 0.01 g MWCNT. Fluid loss and mudcake thickness increased when the mud is exposed to temperature above 250°F. The results showed that xanthan gum with MWCNT gives a better rheological performance.

Flow Pattern Map of Malaysian Crude Oil and Water Two-Phase Flow in a Pipe System

Water produced along with the crude oil during production and transported together in a pipeline is a common occurrence in a petroleum production system. Understanding the behavior of crude oil-water flow in a pipe is crucial to engineering applications such as design and operation of flow lines and wells, and separation systems. Presently, there was no two phase flow study done on the Malaysian waxy crude oil-water. Therefore, a research work was conducted at the Malaysia Petroleum Resources Corporation Institute for Oil and Gas, Universiti Teknologi Malaysia to study the flow pattern of the Malaysian waxy crude oil-water flowing in a closed-loop system at the ambient condition through a 5.08 cm ID stainless steel horizontal pipeline. The research works comprised fluid characterization and flow pattern observation using a video camera camcorder. Five flow patterns have been identified, namely stratified wavy flow, stratified wavy with semi dispersed flow at interface and oil film, dispersion of water in oil and oil continuous with emulsion, dispersion of oil in water with water continuous, and the newly found semi dispersed flow with semi emulsion at interface and thin oil film. The experimental results could be used as a platform to understand better a more complex case of gas, oil, and water flow in a pipeline, which is of utmost importance in designing optimum surface facilities.

Pressure drop and water holdup of Malaysian crude oil and water two-phase flow in pipes

Understanding the pressure drop and water holdup of crude oil-water flow in a pipe is crucial to many engineering applications. Free water in contact with the pipes wall can cause erosion or corrosion problems. An experimental research was conducted at the Malaysia Petroleum Resources Corporation Institute for Oil and Gas, Universiti Teknologi Malaysia to study the pressure drop and water holdup of the Malaysian waxy crude oil-water flowing in a closed-loop system at ambient condition through a 5.08 cm ID stainless steel horizontal pipeline. In the research work, water cuts were varied from 0 - 90% with mixture velocities ranging from 0.1 0.8 m/s. The research works comprised fluid characterization, pressure drop, and liquid holdup measurement.The investigations proved that pressure drop increased with flow rates, while the water holdup was found to have decreased slightly at higher water cuts due to the presence of emulsion in the crude oil a challenge when using a waxy crude oil in a two phase flow system. The experimental results can be used as a platform to understand better a more complex case of liquid-liquid two phase flow.

Drilling fluid waste management in drilling for oil and gas wells

Drilling operation produces two major wastes which are produced water and drilling waste. The drilling waste must be properly managed to ensure no impact to the environment and human. The environmental and human effects of the exposure to drilling waste are discussed in the paper. Different type of drilling fluids has different composition, which influence the environmental impact of the drilling fluid. Due to the potential impact to environment and human, there are regulations by the host government and international conventions for drilling waste management. Generally, oil based drilling fluid is not permitted for offshore disposal and drill cuttings require treatment before disposal. However, water based drilling fluid is allowed for disposal. Synthetic based drilling fluid is preferred due to its technical performance and minimum environmental effects. Main regulations related to environmental and waste management in Malaysia is Environmental Quality Act and Exclusive Economic Zone Act. There are three options of drilling waste disposal, which are offshore disposal, onshore disposal and drill cutting re-injections. Offshore disposal is limited by the regulations while onshore disposal can give additional liability at the disposal site. Drill cuttings re-injection can be a good option of disposal, with zero discharge to the site. However, not all formation is feasible for the re-injection.

Identification of sandstone core damage using scanning electron microscopy

Particles and fluids invasion into the pore spaces causes serious damage to the formation, resulting reduction in petroleum production. In order to prevent permeability damage for a well effectively, the damage mechanisms should be identified. In this study, water-based drilling fluid was compared to oil-based drilling fluids based on microscopic observation. The cores were damaged by several drilling fluid systems. Scanning electron microscope (SEM) was used to observe the damage mechanism caused by the drilling fluids. Results showed that the ester based drilling fluid system caused the most serious damage followed by synthetic oil based system and KCI-polymer system. Fine solids and filtrate migration and emulsion blockage are believed to be the major mechanisms controlling the changes in flow properties for the sandstone samples.

Comparison of rheological and lubricity properties of polymer beads and glass beads in water-based mud

Torque and drag become a major problem in succeeding the extended reach drilling (ERD). One of the techniques used to mitigate torque and drag is using lubricant in water-based mud. In this study, the solid lubricants used were glass beads as it is chemically inert, non-toxic, and non-abrasive, and also the polymer beads of improved physical properties, namely tensile strength and izod impact strength. This study was performed in order to determine the most suitable size of glass and polymer beads that could give the optimum performance of lubricity in drilling mud. The experimental results showed that the rheological properties of water-based mud with glass