Azlinda Azizi

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.

Clarifying the Palm-Based Drilling Fluids Potentials

With the goal of increasing awareness of toxicity level and environmental impact of drilling fluid, and for providing continuous findings for a better drilling fluid formulation, an experimental work based on a rheological evaluation of drilling fluid was carried out. The use of palm-based and palm oil-based as an alternative base component in drilling fluid formulation have been explored in terms of sand content, pH, viscosity, yield point and gel strength. Standard laboratory formulation including distilled water, sodium hydroxide, bentonite, barite and 1,2-propylene glycol were used in this study. Tests conducted on palm-based drilling fluid with properties of 17.0 ppg and 80/20 oil-water ratio revealed that palm methyl ester C14 and palm kernel oil have sand content of less than 0.5 % vol. with excellent thermal resistance on high temperature for palm kernel oil based.

Effective Bridging Agent Particle Sizes of Reservoir Drilling Mud

The optimization of bridging agent size selection in drilling mud is now critically demanding due to the desired pressure to produce the non-damaging fluid or low damaging fluid. Bridging agent is the materials that can give effect on minimizing fluid invasion and optimize the sealing operations. Three different sizes of bridging agents were prepared, Fine (F), Medium (M) and Coarse (C) size where calcium carbonates had been selected as the bridging agents. Water Based Mud had been chosen as based of drilling mud to be investigated. Experiments conducted were rheology and filtration test. The study shows that the mud weight was increase with increasing size of bridging agent. The filtration test showed a high fluid loss in mud samples without bridging agent (Mud A) and least fluid loss in Mud B. Thus, the fine size of bridging agent can form better filter cake and prevent the fluid being loss too much thus reducing the damage to the reservoir wellbore.

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.

Performance evaluation of agarwood distillation waste as retarder for high strength oilwell cement

Cement strength must be carefully maintained so that the cement is able to sustain formation stresses without failing. Such a mechanical failure in a cement sheath can cause a loss of annular isolation. A synthetic polymer cement retarder has been designed to provide extended pumping times for cement slurries, while having minimal effect on compressive strength development. However, it is difficult to select a retarder that can suit a wide range of field conditions. Fluid loss control can also be affected by the addition of a retarder, especially at high temperatures. Addition of retarder sometimes may increase the viscosity and pumping pressure of the slurry and may result in fracturing of the hydrocarbon bearing zone and costly job failure. The main idea for this study is to determine whether Agarwood waste from distillation process (AGW) can be used as a retarder in oil well cement with excellent compressive strength development. The compressive strength developments were evaluated at different curing time and particle sizes of AGW which are 90 μm, 150μm and 250μm. The performance of AGW slurries were compared with commercial retarder slurry. Apart from that, chemical analysis on AGW was conducted by using X-ray Fluorescent (XRF) to determine the presence of cementations component in this material. All cement testing procedures should follow API recommended specification 10B standard. From the results obtained, the performance of 250 μm of AGW is better than commercial retarder by 10% increment in the development of cement strength.

Potential of Five-Leaved Chaste Tree (Vitex negundo L.) Leaves as Source of Natural Dye from Supercritical Carbon Dioxide (SC-CO2) Extraction

Natural dyes represent a sustainable source of colorants, which are low cost and safer than synthetic dyes, concerning human health. The purpose of this study is to extract Vitex negundo L. leaves using supercritical carbon dioxide extraction and to identify the extracts potential as a dye. The extraction process has been conducted at different operating conditions by varying temperature from 40 to 65°C with an increment of 5°C at 20, 25, and 30 MPa within 60 minutes constant time. The extracts obtained at different conditions were analyzed using Gas Chromatography Mass Spectrometer (GC-MS) to determine the chemical compounds present. Increase of temperature increased the extraction yield, but further increasing the temperature above 50°C has reduced the yield. The effect of pressure gave two different patterns, in which the first one showed the yield kept increasing with pressure (20 to 30 MPa) at 40, 45, 50, and 55°C. The second pattern showed sudden reduction of yield above 25 MPa at another two higher temperatures. The highest extraction yield (13.94 mg/g) was obtained at 30 MPa and 50°C which considered as optimum operating condition. GC-MS analysis showed the presence of several phytochemicals including some flavonoid compounds, which are potential sources of dye.

The Effect of Lemongrass as Lost Circulation Material (LCM) to the Filtrate and Filter Cake Formation

Lost circulation is one of the most troublesome encountered in drilling due to uncontrolled flow of mud into the formation that likely to be caused of unsuccessful filter cake. The lost circulation material (LCM) is the additives that added to the drilling fluid to control loss of mud to the formation. In this research, the lemongrass was used as LCM. The objectives of this experiment are to investigate the effect of lemongrass as LCM to the filtrate and filter cake thickness and to determine the effective size of lemongrass as LCM. The experiments were conducted to measure the filtrate and filter cake thickness with different size and different based of drilling fluid. Low Pressure Low Temperature (LPLT) filter press is for water based mud (WBM) and High Pressure High Temperature (HPHT) filter press is for oil based mud (OBM) were used to perform the filtration process under static condition and constant filtration time which is 30 minutes. Both WBM and OBM are prepared four samples with three difference sizes of LCM and native mud. The sizes of lemongrass are 150 microns, 250 microns and 500 microns. After each experiment, the filtrate volume and filter cake thickness were determined to represent. The result shows that lemongrass able to perform a good LCM in both WBM and OBM based on filtrate volume and filter cake thickness. For WBM, the mud with LCM is lower filtrate volume than native mud which is less than 6.0 ml and for OBM, the mud with LCM is lower filtrate volume than native mud which is less than 5.0 ml. Both WBM and OBM show the thickness of filter cake obtained was in the range of 2 to 25 mm. The result also shows that the effective size of LCM is 150 micron due to less filtrate volume and filter cake thickness compare to other size of LCM which is 250 microns and 500 microns. The findings revealed that then lemongrass with the size of 150 microns is the suitable material to be used as LCM to replace conventional LCM.