Effah Yahya

Rheological study of nanosilica based drilling fluid

In drilling and well completion operations, drilling fluid is a crucial element as it is employed for the purposes of several functions. The main functions of drilling fluid are to control formation pressure, maintain the wellbore stability, transport the cuttings up to surface to clean the borehole bottom as well as to lubricate and cool the drill bit. Moreover, it is used to minimize the drilling damage to reservoir and suspend cuttings when the pumping is stop, hence it will not falling back down the borehole. The purpose of this study is to formulate new drilling mud formulation modified with nanosilica. Six samples of water based mud (WBM) were prepared using three types of polymers, (Xanthan Gum, Hydro Zan Plus and Hydro Star HT), starch and nanosilica. Basic rheological tests such as density, viscosity and pH were carried out. The density test was carried out using mud balance meanwhile the pH test was using pH meter. The plastic viscosity, yield point and gel strength tests were carried out using viscometer. Besides that, physical observation was also performed for as the stability test. The results concluded that water based mud incorporated with polymer Hydro Zan Plus and nanosilica can be a potential candidate to be commercialized as a smart nanodrilling fluid.

Nanoemulsion Applications in Enhanced Oil Recovery and Wellbore Cleaning: An Overview

This article is an overview of potential applications of nanoemulsion as a promising candidates for enhanced oil recovery (EOR) and as a medium for wellbore cleaning. Nanoemulsion is an emulsion that has nanosize particle distributions in the range of below 500 nm. It also has lower interfacial tension (IFT) as low as the value of 0.001 mN/m. The small particle size distributions in nanoemulsion resulted the good properties of nanoemulsion in term of large surface area. This excellent property will improve the sweeping efficiency of the oil droplet in the reservoir and finally increase the oil recovery. Besides that, the unique features possess by nanoemulsion make it suitable as superior wellbore cleaner as compared to conventional detergent-based cleaner. Thus, the significance of nanoemulsion becomes the major highlight in oil and gas industry. This overview on nanoemulsion applications is imperative and necessary in order to provide an insight for the future development and perhaps open a door to extend the applications of nanoemulsion to other more challenging areas.

Solubility Determination of Tamarind Seeds Extracts by Using Supercritical CO2 Extraction

In recent years, tamarind seeds extracts are used widely in food, pharmaceutical and textile industry due to unique functions as cooking oil, antibacterial and thickening agent. In this study, a simple static technique is used to obtain the solubility of tamarind seed in supercritical carbon dioxide because there is no study on that yet. The solubility measured is performed at temperatures and pressures ranging from 40oC, 60oC, 80oC and 3000psi, 5000psi and 7000psi respectively; resulting in mass fractions in the 6.00 x 10-8 to 5.84 x 10-7 range. The Chrastil model is used to correlate the experimental data. The oil yield extract in range of 0.0375 to 0.365g.

Saccharomyces cerevisiae from Baker’s Yeast for Lower Oil Viscosity and Beneficial Metabolite to Improve Oil Recovery: An Overview

This article is an overview of microbial enhanced oil recovery (MEOR) and the potential of Saccharomyces Cerevisiae to be applied in MEOR. MEOR may have same mechanisms with commercial enhanced oil recovery (EOR) but it used biological approach in improving oil recovery. Saccharomyces Cerevisiae produced carbon dioxide and ethanol under anaerobic condition. The carbon dioxide and ethanol that produced by this microbe are two from the six main MEOR agents in improving oil recovery. This articles also discussed on previous MEOR pilot projects that were conducted in Argentina, China and Malaysia.

The Optimum Number of Trays and Solvent Circulation Rate in Removing Acid Gases in Absorption Unit

Removal of acid gases from natural gas is very important as to meet the sale’s specifications and environmental regulations. It is also a measure to minimize the corrosion effects. The most common process to remove the acid gases is amine process. There are some operating parameters which can be considered to optimize amine sweetening plant such as inlet gas temperature, lean amine circulation rate, lean amine temperature, amine concentration, number of trays and others. The objectives of the project are to study the optimum number of trays of absorber and amine circulation rate in removing acid gases in absorption unit using HYSYS simulator which capable in designing the process. By using HYSYS software, a base case of amine sweetening unit was created and di-ethanolamine (DEA) is used as the amine solvent. Four samples at different concentrations of acid gases were tested. The rules evaluated include 20 trays in the absorber and higher circulation rate. Although these rules of thumb are excellent as the starting points, violating these rules could offer considerable advantages to process efficiency. Depending on the concentration of the acid gases at the feed stream, every situation is different and requires a thorough investigation whether some changes are beneficial or not.

Relationship between Foamability and Nanoparticle Concentration of Carbon Dioxide (CO2) Foam for Enhanced Oil Recovery (EOR)

Foam stability can be uttered in foamability measurement and bubble size dispersal. The higher the foamability, the more stable it is. The addition of nanosilica particle to the foam system will further improve the rigidity of the lamellae interface by providing stickiness force between foam lamellae and its surface, halting the film thinning and prevent it from rupture. This paper aims to investigate the stability of CO2 foam with addition of nanoparticle, to find the optimum surfactant and nanoparticle concentration that achieved higher foam stability, to determine the relationship between the foamability and the nanoparticle concentration within the carbon dioxide foam system and also to analyze the effect of crude oil on foam stability. For this experiment, foam generator was used. The concentrations of surfactant were prepared at ranges from 500 ppm to 5000 ppm. The foam stability test was conducted at constant pressure, temperature and flowrate. The nanoparticle was used with set of different concentrations such as 1000 ppm, 3000 ppm and 5000 ppm. It was found that the increases in both surfactant and nanoparticle concentration have boosted up the stability of the foam produced from 92% to 100% foamability and foam durability extended to maximum of 5 hours. The optimum concentration of both surfactant and nanoparticle was 5000 ppm. It is important to determine the relationship between foamability and nanoparticle concentration, so that foam stability, mobility and the morphology of the foam produced can be forecasted with the newly breakthrough nanoparticles technology.