POTENTIAL SEPIOLITE AS A SUBSTITUTE MATERIAL FOR DRILLING FLUID

In this study, rheological behavior of Sepiolite as a drilling fluid are investigated and comparison study between rheological properties of Bentonite with Sepiolite has been made to ensure optimum value of Sepiolite rheological properties. In high salt contamination and high temperature well, the utilization of Bentonite mud system lead to undesirable rheological performance. Hence, process of removing drilling cuttings is disturbed; unacceptable fluid losses and optimum equivalent circulation density (ECD) can not be achieved. This research is focus on rheological properties of Sepiolite at vanous temperatures and brine concentrations for instances at 150°F and 250°F of 16 hours hot rolled. Semi saturated and saturated brine of 5 lb and 10 lb potassium chloride are formulated in Sepiolite mud system. Furthermore, contradistinction analysis between Bentonite and Sepiolite are analyzed to confirm the efficacious of Sepiolite performance. In order to design an effective drilling fluid system, fresh water is mixed with potassium chloride to obtain a brine solution. Soda ash which is hardness material is added in the solution and mixed for duration of 1 minute. Next, caustic soda is circulated into the solution for about 5 minute. The function of this chemical is to adjust pH value between 9.0 and 9.5. After that, HYDRO PAC-LV is added and mixed for 5 minutes followed by Bentonite. Last but not least, barite is added for 20 minutes as a weighting agent. In conclusion, Sepiolite mud system performs better than Sabah and India Bentonite. Based on the pattern achieved from laboratory experiment, Sepiolite gives best rheological values followed by Sabah Bentonite and India Bentonite. Nevertheless, Sepiolite mud system exhibits highest fluid loss compare to the other Bentonite. This situation can be treated by using higher performance of fluid loss reducer

POTENTIAL SEPIOLITE AS A SUBSTITUTE MATERIAL FOR DRILLING FLUID

In this study, rheological behavior of Sepiolite as a drilling fluid are investigated and comparison study between rheological properties of Bentonite with Sepiolite has been made to ensure optimum value of Sepiolite rheological properties. In high salt contamination and high temperature well, the utilization of Bentonite mud system lead to undesirable rheological performance. Hence, process of removing drilling cuttings is disturbed; unacceptable fluid losses and optimum equivalent circulation density (ECD) can not be achieved. This research is focus on rheological properties of Sepiolite at vanous temperatures and brine concentrations for instances at 150°F and 250°F of 16 hours hot rolled. Semi saturated and saturated brine of 5 lb and 10 lb potassium chloride are formulated in Sepiolite mud system. Furthermore, contradistinction analysis between Bentonite and Sepiolite are analyzed to confirm the efficacious of Sepiolite performance. In order to design an effective drilling fluid system, fresh water is mixed with potassium chloride to obtain a brine solution. Soda ash which is hardness material is added in the solution and mixed for duration of 1 minute. Next, caustic soda is circulated into the solution for about 5 minute. The function of this chemical is to adjust pH value between 9.0 and 9.5. After that, HYDRO PAC-LV is added and mixed for 5 minutes followed by Bentonite. Last but not least, barite is added for 20 minutes as a weighting agent. In conclusion, Sepiolite mud system performs better than Sabah and India Bentonite. Based on the pattern achieved from laboratory experiment, Sepiolite gives best rheological values followed by Sabah Bentonite and India Bentonite. Nevertheless, Sepiolite mud system exhibits highest fluid loss compare to the other Bentonite. This situation can be treated by using higher performance of fluid loss reducer

Critical rate analysis for CO2 injection in depleted gas field, Sarawak Basin, offshore East Malaysia

This study aimed to address the challenges and strategies to determine the critical rate of CO2 injection into a carbonate depleted gas field. In this research, the critical rate is the maximum allowable injection rate before formation damage initiation. The cause of formation damage could be due to in-situ mobilization or trapping of migratory fines resulting in plugging the flow path. This study performed a thorough investigation of a different rock-fluid system to evaluate the safe injection limit, as the critical rate is different for each rock-fluid system. The geochemical effect of CO2 injection toward carbonate formation was also investigated in this research. Other than that, the porosity and permeability changes due to CO2-brine-rock multiphase flow characteristics were considered to understand the feasibility of CO2 sequestration into carbonate formation. This research discussed experimental design to mimic the CO2 injection scenario of CO2 into carbonate depleted gas field. Therefore, several core flooding experiments were conducted under reservoir conditions using representative native cores, CO2, and synthetic formation brine. Abrupt changes in differential pressure (ΔP), analysis of effluent collected after CO2 multi-rate flow, and pH reading are the key indicators to consider that the condition has reached a critical rate. The experimental result demonstrated the existence of fines migration, scale formation, and salt precipitation after the core was subjected to supercritical CO2 multi-rate flow. Considering these issues and challenges associated with injectivity, this study recommended a maximum injection rate prior to field scale injection