With a continued growth in the discovering of new reserves at deeper depths in mature fields, drilling through the depleted and already producing zones is already posing a loss circulation problem as well as other wellbore instability problems such as stuck pipe. Considering the cost of loss circulation materials and its effectiveness the need to source materials locally for LCMs becomes imperative. This research work investigated palm kernel shell as a local material to be used as loss circulation material, the processed palm kernel shell was sieved into different particle sizes and added in various mass ratio to the formulated mud. The mud weight, filtration test and permeability plugging test was done to experimentally characterize the mud based on its effectiveness as a loss circulation material. Palm kernel shell with blends of other industry loss circulation material was also considered to ascertain the blended LCMs effectiveness as compared to the palm kernel shell mud samples. From the experiments conducted, the mud weight of palm kernel shell mud samples ranges from 11ppg to 11.4ppg in different particle size distribution. The total filtrate loss and the filter cake thickness ranges between 5.0ml to 8.6ml and 1mm/32-inch to 2mm/32-inch respectively. The permeability plugging test of the Palm kernel shell mud samples has a range of total filtrate volume of 8.9 ml to 11ml, as well as filter cake thickness of 3mm/16-inch to 4.5mm/16-inch. In a comparative analysis, the blend LCMs, i.e. the palm kernel shell and Mica, palm kernel shell and graphite have a better sealing and filtrate loss properties than the palm kernel shell mud samples. It is therefore recommended that more research should be carried out on the blends of palm kernel shell and other LCMs as it will be cost effective when compared to the imported LCMs.

This study attempts to show the effectiveness of using coconut fibre as a loss circulation material in drilling operation. The research incorporated a practical approach. Laboratory experiments was conducted to design drilling muds with the desired loss circulation materials. Their rheological properties and permeability plugging ability was ascertained and compared to determine the most effective loss circulation material blend. To formulate the loss circulation materials, the coconut fibre was processed and particle sizing distribution was conducted on the processed coconut fibre. The coconut fibre was separated into coarse sizes (3350, 2360, 1700 and 1180) and medium be sizes (850 and 425). The distinction between the formulated muds is the loss circulation material combination in them. The three drilling muds had medium-coarse coconut fibre ratio of 60:40, 40:60 and 30:70. The rheological properties of each drilling mud was determined to show suitability of use as a drilling fluid. Experimental results showed similar rheological properties for each mud and they are all suitable for use. The PPT test and ES test were conducted on the mud samples as well. These experiments were conducted at a desired temperature of 200°C and filter press pressure of 1500psi. The thickness of the produced mud cake was measured. By comparing the amount of unrecovered fluid (fluid loss), the least fluid loss was observed in the mud with medium-coarse coconut fiber combination of 60:40

Drilling fluid are complex fluids consisting of several additives. These additives are added to enhance and control the rheological properties (such as viscosity, gel strength and yield point) of the mud. These properties are controlled for effective drilling of a well. This research work is focused on determining the rheological behavior of drilling mud using industry-based polymer and Irvingia Gabonensis (ogbono) as viscosifiers. Water based muds were formulated from the aforementioned locally sourced viscosifier and that of the conventional used viscosifier (Carboxylmetyl cellulose, CMC). Laboratory tests were carried out on the different muds formulated and their rheological properties (such as yield stress, shear stress, plastic viscosity and shear rate) are evaluated. The concentration of the viscosifiers were varied. The expected outcome of the research work aims at lowering the total drilling cost by reducing the importation of foreign polymer which promotes the development of local content in the oil and gas industry. The research compares the rheology of mud samples and the effect of varying the concentration (2g, 4g, 6g, 8g, and 10g) of both CMC and Ogbono and determining the changes in their rheological properties. The total volume of each mud sample is equivalent to 350ml which represent one barrel (42gal) in the lab. From the result, at concentration of 2g, the ogbono mud has a better rheology than the CMC mud, but at a concentration above 2g, CMC mud shows a better rheology than ogbono mud, that is, as the concentration of CMC is increased, the rheological properties of the mud increased while as the concentration of ogbono is increased the rheological properties decreased. The viscosity of the drilling fluid produced from the ogbono were lower than that of CMC, it could be used together with another local product such as cassava starch, offor or to further improve the rheology and then be a substitute to the conventional viscosifiers.