This chapter focuses on the development of solid control system that is suited for drilling 12.25-inch hole. The first part discusses the performance of rate of penetration (ROP), equivalent circulating density (ECD) and drill string drag while the second part of the chapter discusses about the effect of solid control system performance to mud properties plastic viscosity (PV), yield point (YP), and low gravity solid (LGS). The input parameters were gathered from two different set up of solid control systems that were used in Well A and Well B. The result is mainly based on the performance of original solid control system new design vs. old design. Installation of distributor tank and channeling the mud to respective shale shakers significantly enhanced the system and operational performance. The ROP at 12.25-inch drilling was improved by 20%. New design, on an average, improved the ECD margin by reducing additional pressure exerted using original mud from 4.9 to 2.9%. High ECD margin is not recommended because it can break the weak formation. Mud properties while drilling the 12.25-inch hole section; PV, YP and LGS values were improved by 14, 17, and 25% respectively.

Surface modification is one of several techniques on improving the characteristic of certain elements. The surface of material can be modified by coating it with certain coating material. In this study Aluminium Oxide (Al₂O₃) nanoparticles (NPs) is used and its coating material are Oleic Acid and Silica Dioxide. The main objectives of this study are to observe the properties of Al₂O₃ NPs after being coated with OA and SiO₂ at paraffin oil and brine water interface and to investigate the changes of NPs structure and chemical properties using three analysis which are Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR) and X-Ray Powder Diffraction (XRD). Al₂O₃ NPs was coated with OA and then followed by SiO₂ coating. After that, the modified NPs was analyzed by these analysis (SEM, FTIR and XRD). The modified Al₂O₃ NPs then were injected into mixture of paraffin oil and brine water. Al₂O₃ NPs coated with OA inhibit hydrophobic tails which prevent the molecules of NPs to mix with water. While for NPs coated with SiO₂, its aggregate well at the interface and most of it sticking to test tube wall. However, some of the NPs dissolve in water. SEM analysis images of before and after coating show different in thickness indicate the successfulness in coating. OA and SiO₂ can be seen attach to Al₂O₃ NPs quasi-spherical surface. While FTIR and XRD peaks show that there are changes in chemical properties and existence of contaminant at Al₂O₃ NPs crystallite structure. These analysis and observation of NPs confirming the successful of coating. Thus, can help in detection of crude oil production and improve the performance of Al₂O₃ NPs.

In this study, effect of casing imperfection on the casing strength in thermal environment of steam injection wells was investigated. The imperfections were modelled in the form of casing pits which may represent local cavitation, wear or corrosion attacks. Several pits with various depths (C) relative to the casing thickness (t) and different casing diameter to thickness (D/t) ratios were considered in this study. For the purpose of investigation, 3D FE models consisting of defective casing-cement-formation system were developed. N80 casing with the casing length of 3.048 m is analyzed in the numerical study. In the analysis, the combined effects of cyclic thermal stress (from 25 °C to 360 °C), collapse pressure (from formation) and defects on casing were taken into account. From the numerical study, it is found that the casing imperfection greatly affected the casing strength in steam injection wells. The presence of pits markedly reduces the casing collapse strength in comparison to that of non-defective casing. For instance, the collapse strength of casing having 2 pits along its circumferential direction with depth C = 0.5t reduced about 49% and 43% for D/t = 22.09 and D/t = 17.26, respectively. In addition, the combination of high temperature, imperfection factor and formation pressure induces severe deformation on casing, even at lower formation pressure.