For offshore wells requiring sand control, Open Hole Gravel Packing (OHGP) with or without shunted screen technology is a common completion technique. Prior to this paper, there has been no application of shunted screen OHGP in High-Pressure High-Temperature (HPHT) environment due to lack of a viscous fluid availability in high-density divalent brines (> 14.6 lbm/U.S. gal). For the case study, the fluid requirements in terms of density and temperature were 15.4 lbm/U.S. gal and 265°F, respectively. The only brine option at this density was a blend of calcium chloride/bromide and zinc bromide. In this brine and density, none of the existing fluids work hence a novel polymer-based fluid had to be developed. The fluid had to pass the following tests a) rheology before and after subjecting to high shear of both uncontaminated and contaminated fluids at 3 different temperatures b) sand settling tests at 4 different temperatures c) Production Screen Tester to ensure the fluid does not plug the screens during the job. System Integration Tests (SIT) were performed to ensure the mixing equipment would be able to batch mix the fluid and actual pumping equipment would function properly with the fluid. The field trial planning included simulations, pre-job meetings, and fluid management plan. The job was executed as per the procedure outlined during pre-job meetings. This paper discusses laboratory development, yard test qualification, and successful shunted screen OHGP case history of a novel 15.4 lbm/U.S. gal viscous gravel pack carrier fluid.

This paper discusses complexities and challenges of managing boil off gas (BOG) in LNG liquefaction plants. Most publications in the past have focused on regasification terminals and have not addressed the area of liquefaction plants. The paper discusses the generation and management of BOG and the associated networks and machinery to manage it. BOG Options available for both greenfield plants and in debottlenecking situations are covered. The advantages and disadvantages of different options and compressor systems are covered and the concept of dynamic simulation as an analysis tool is addressed.

This paper discusses complexities and challenges of managing boil off gas (BOG) in liquefied natural gas (LNG) liquefaction plants. Most publications in the past have focused on regasification terminals and have not addressed the area of liquefaction plants. The paper discusses the generation and management of BOG and the associated networks and machinery to manage it. BOG options available for both Greenfield plants and in debottlenecking situations are covered. The advantages and disadvantages of different options and compressor systems are covered and the concept of dynamic simulation as an analysis tool is addressed.

Synchronous motor driven centrifugal compressors are widely used in the oil and gas industry. In evaluating the optimum selection of synchronous motor drivers for centrifugal compressors, it is important to understand the factors influencing a proper match for a centrifugal compressor and its synchronous motor driver. The buyer should specify process requirements and define possible operating scenarios for the entire life of the motor driven centrifugal compressor train. The compressor designer will use the buyer-specified process conditions to model the aerothermodynamic behavior of the compressor and characterize its performance. Performance, controllability, starting capabilities as well as the optimum power margin required for a future-oriented design must also be considered. This paper reviews the criteria for evaluating the optimal combination of a centrifugal compressor and its synchronous motor driver as an integral package. It also addresses API standard requirements on synchronous motor driven centrifugal compressors. Design considerations for optimal selection and proper sizing of compressor drivers include large starting torque requirements to enable compressor start from settle-out conditions and to prevent flaring are addressed. Start-up capabilities of the motor driver can significantly impact the reliability and operability of the compressor train. API 617 on centrifugal compressors refers to API 546 for synchronous motor drivers. In this paper, requirements of API 617 and 546 are reviewed and several important design and sizing requirements are presented. In the effort to optimize plant design, and maintain the performance requirements, the paper discusses optimization options, such as direct on-line starting method to explore the motor rating limits, and the use of synchronous motors for power factor correction to eliminate or reduce the need for reactive power compensation by capacitor banks. This paper presents a novel approach to show constant reactive power lines on traditional V curves. It also complements capability curves of synchronous motors with lines of constant efficiency. The paper discusses variable frequency drive options currently used for synchronous motors in compressor applications. The paper addresses the available variable frequency drive types, their impact on the electrical grid, and motor design considerations with a view to summarizing factors important to the selection of variable frequency drives.

High thermal efficiency of LNG liquefaction plants is of importance in order to minimize feed usage and to reduce CO2 emissions. The need for high efficiency becomes important in gas constrained situations where savings in fuel auto consumption of the plant for liquefaction chilling and power generation can be converted into LNG production and also from the standpoint of CO2 reduction. This paper will provide a comprehensive overview of waste heat recovery approaches in LNG Liquefaction facilities as a measure to boost thermal efficiency and reduce fuel auto-consumption. The paper will cover types of heating media, the need and use of heat for process applications, the use of hot oil, steam and water for process applications and direct recovery of waste heat. Cogeneration and combined cycle approaches for LNG liquefaction will also be presented along with thermal designs. Parametric studies and cycle studies relating to waste heat recovery from gas turbines used in LNG liquefaction plants will be provided. The economic viability of waste heat recovery and the extent to which heat integration is deployed will depend on the magnitude of the accrual of operating cost savings, and their ability to counteract the initial capital outlay. Savings can be in the form of reduced fuel gas costs and reduced carbon dioxide taxes. Ultimately the impact of these savings will depend on the owner’s measurement of the value of fuel gas; whether fuel usage is accounted for as lost feed or lost product. The negative impacts include the reduction in nitrogen rejection that occurs with reduced fuel gas usage and the power restrictions imposed on gas turbine drivers due to the increased exhaust system back-pressure caused by the presence of the WHRU. When steam systems are acceptable, a cogeneration type liquefaction facility can be attractive. In addition to steam generation and hot oil heating, newer concepts such as the use of ORCs or supercritical CO2 cycles will also be addressed.