The effect of testing conditions on lost circulation materials\u27 performance in simulated fractures

Lost circulation (LOC) problems increase costs of drilling significantly. It is not only the cost of the drilling fluid that is lost into the formation but also the costs of subsequent problems that can be higher than the cost of the drilling fluids. LOC also possibly leads to a serious risk of blowout incident. Lost circulation materials (LCM) are regularly added to the drilling fluids with an expectation of plugging the flow path. Due to the difficulties of testing and monitoring LCM sealing processes in the field, LCM evaluation in the laboratory is often used to prove and assure successful treatment. Investigating LCM behavior and the causation of obtaining different results would expand the reliability of the laboratory evaluation methods. In this study, a steel cylindrical cell was used to simulate downhole high-pressure conditions. Steel discs with precisely sized slots (simulating wellbore fractures) were used to study the effect of testing conditions on the particulate LCM sealing performance. Results show that the fracture wall angles, the disc thickness, the base fluids, the drilling fluid density, the particle size of weighting materials related to the LCM grain sizes, and the dynamic aging conditions all affect the testing results significantly. LCM that performed well in the slow injection rate tests also exhibited sealing behavior effectively in the instantaneous flow conditions. The experiments provided an understanding of the fracture sealing mechanism to be applied in improving the laboratory evaluation methods and field treatment design. This knowledge is useful for both the preventive and corrective LOC mitigating approaches --Abstract, page iv

ปัจจัยเสี่ยงในการเกิดโรคอุจจาระร่วงเฉียบพลันในกลุ่มเด็กอายุต่ำกว่า 5 ปี จังหวัดปัตตานี

Master of Science (Research Methodology

Seal Glass for Solid Oxide Fuel Cells

Barium calcium aluminum boro-silicate glass (BCABS) is used as a sealant for Solid Oxide Fuel Cells (SOFCs) to protect against air and hydrogen gas leaking at 800°C. One major problem is the chemical reaction of this glass with barium oxide and other materials in the composition such as Ba-Y-Co-Fe (BYCF) and Ba-Sr-Co-Fe (cathode) used in the fuel cell components, leading to the formation and spreading of barium aluminosilicate glass on the cathode surface in the fuel cell. This investigation indicated that adding 0.4 mol% ZrO2 to BCABS prevents the formation of barium aluminosilicate glass. Generally, the sealing glass of fuel cells must show high resistivity for no disturbance to electricity from the fuel cell system when generating the electron. The 0.4 mol% ZrO2 to BCABS is generated with resistivity of 4 MΩ that is useful for SOFCs technology. The thermal expansion coefficient (TEC) in SOFCs is the major condition for producing the cell layers. The thermal expansion coefficient of SOFCs based on each layer (cathode, electrolyte, anode, interconnect and sealant) should be closed to prevent broken cells. The thermal expansion coefficient is 12.40 × 10−6/oC matched with the TEC of the GDC10 electrolyte. Therefore, BCABS glass with 0.4 mol%ZrO2 generated a novel composite for SOFCs

LINKAGE AND INTEGRATION WORK OF COMMUNITY WELFARE NETWORK WITH GOVERNMENT AGENCIES IN UTTARADIT PROVINCE, THAILAND

Community welfare is driven by outside motivation, which results in adaptation of the community to the care of one another in the form of welfare. From this factor, Uttaradit province is awake and developing the model of community welfare. So it brings to overview the work of Uttaradit Community Welfare Fund Network in Thailand (Ut-CWFN).  The study was qualitative research. The instrument used in this study was in-depth interview.  The  objectives   of  the  study  were 1)  to the process of  implementation  of  (Ut-CWFN) and 2)  to pattern of linkage  and  integration  of   (Ut-CWFN) by in – depth  interviews  and  participant with 10 keys leader in (Ut-CWFN). Inclusion criteria from the volunteer sacrifice of the previous welfare fund work. And people in the community trust to represent the network. Data analysis by content analysis. The results of the study were as follows: 1) Process driven network of (Ut-CWFN) caused by participation of member, community, private and government. 2) Pattern of linkage and integration of   (Ut-CWFN) with associate. The factors listed above to represent the region in driving Community Welfare Fund national policy in Thailand.This study show that mix welfare, integrate, associate and network support to the fund is strong equality and sustainable fund.&nbsp

The Focal Determinants of Service Fairness and Service Recovery Satisfaction in Cloud Computing

The purpose of this study is to analyze the implications of service fairness on satisfaction recovery in business relationships. Adopting a service fairness perspective on cloud computing business directs suppliers’ focus in business relationships towards engaging with their customers’ service recovery satisfaction. In the article it is demonstrated that a service fairness perspective is multi-dimensional (structural and social), enabling the creation of recovery satisfaction, which enhances continued usage of cloud computing system. This perspective enables marketers to better understand how to develop and extend structural and social service fairness through equally service delivery and fair treatment relevant to their businesses

Integrating Service Fairness Into The Post-Acceptance Model Of Is Continuance In Cloud Computing

This study integrates service fairness into a post-acceptance model of information system continuance. This study added constructs based on Greenberg’s (1993) four-component taxonomy of organizational justice. The research model seeks to be useful in predicting satisfaction, which enhances continued usage of an IS. The results show that perceived usefulness and satisfaction influence continuance intention, as the post-acceptance model predicts. Three of the four distinct service fairness dimensions, systemic, configural and interpersonal fairness, significantly enhanced satisfaction. However, the relationship between informational fairness and satisfaction was negative and significant

Critical control in transcritical shallow-water flow over two obstacles

The nonlinear shallow-water equations are often used to model flow over topography. In this paper we use these equations both analytically and numerically to study flow over two widely separated localised obstacles, and compare the outcome with the corresponding flow over a single localised obstacle. Initially we assume uniform flow with constant water depth, which is then perturbed by the obstacles. The upstream flow can be characterised as subcritical, supercritical and transcritical, respectively. We review the well-known theory for flow over a single localised obstacle, where in the transcritical regime the flow is characterised by a local hydraulic flow over the obstacle, contained between an elevation shock propagating upstream and a depression shock propagating downstream. Classical shock closure conditions are used to determine these shocks. Then we show that the same approach can be used to describe the flow over two widely spaced localised obstacles. The flow development can be characterised by two stages. The first stage is the generation of upstream elevation shock and downstream depression shock from each obstacle alone, isolated from the other obstacle. The second stage is the interaction of two shocks between the two obstacles, followed by an adjustment to a hydraulic flow over both obstacles, with criticality being controlled by the higher of the two obstacles, and by the second obstacle when they have equal heights. This hydraulic flow is terminated by an elevation shock propagating upstream of the first obstacle and a depression shock propagating downstream of the second obstacle. A weakly nonlinear model for sufficiently small obstacles is developed to describe this second stage. The theoretical results are compared with fully nonlinear simulations obtained using a well-balanced finite-volume method. The analytical results agree quite well with the nonlinear simulations for sufficiently small obstacles