Kuwait Oil Company (KOC) owns and operates several Oil & Gas fields and Pipeline networks in Kuwait and is responsible for exploration, development, production and operation of Kuwait's Hydrocarbon assets. The oil fields in the western part of the state predominantly produces high sour gas and normally the compressed sour gas is transported to downstream refineries for treatment, wherein the Acid Gas Removal Plants extract the sulfur contents in the gas received by treating it with regenerative Amine based treating processes for removing acidic impurities such as H2S, CO2 and organic Sulphur compounds. The country has been long battling with the limitations in downstream sector such as limited handling capacity, unplanned shutdowns, and delay in their expansion projects. This created huge bottlenecks for the upstream unit of KOC which consequently resulted in operational disturbances and gas flaring beyond the company's global flaring target of < 1%. To overcome these challenges, a comprehensive study was carried out for sour gas handling in the State of Kuwait and installation of Gas Sweetening Facility (NGSF) within KOC was considered imperative. However, the process of project delivery was a great challenge due to emerging operational approaches and conflicts with expansion projects in refinery. Thus, breakthrough solutions were set out deploying appropriate core technologies. This paper discusses the challenges at length and the innovative solutions implemented which were intended to optimize the production and utilization of gas in support of energy requirements for the State.
This paper discusses a case study regarding a stuck pig in a non-metallic pipeline used for effluent water service. The line was pigged and half way through the operation, the pig got stuck in the pipeline. The exact location of the pig was not known and huge sludge volume was recovered at the receiving station. Several attempts were made to release the stuck pig; these attempts were constrained by the nature of the non-metallic pipeline and its design. Through collaboration with the downstream section of Kuwait Oil Company, we were able to free the stuck pig and continue the pigging operation. Ideas that were considered and implemented to free the pig will be shared and the method chosen and implemented.
Kuwait Oil Company (KOC) owns and operates eight Gas Booster Stations with around 38 Gas Turbine drivers. These Turbines work on the Brayton Cycle exhausting hot gases to the atmosphere in an Open Cycle. Every 100 MW of Open Cycle Gas Turbine has the potential to generate 50 MW of electrical energy out of exhaust heat recovery. Considering the total installed number of Gas Turbines, there is the potential to generate 450 MW of electrical energy. The study to recover this energy, which is currently wasted, is the subject of this paper. Traditionally the heat is recovered from the exhaust of the Gas Turbines by diverting the exhaust of the Turbines through a Heat Recovery Seam Generator. In the conventional system, the working fluid is water, which is converted into steam, which turns a steam turbo-generator. Furthermore, large quantity of water is required for cooling the steam condenser. As all the Company's Booster Stations are at dessert type of locations with difficulty in sourcing fresh water for the working fluid and seawater for condenser cooling, hence the idea did not takeoff. We have now come to know of a heat recovery system which uses Cyclopentane as working fluid and ambient air for condenser cooling. A Thermal fluid is interposed between the exhaust gases and the Cyclopentane loop to transfer heat from the exhaust gas to the Cyclopentane loop. The pressures in the Cyclopentane loop is maintained in such a way that the heat from the Thermal Fluid converts the Cyclopentane to superheated vapor and the air in the condenser condenses it after passing through a power turbine to recover the mechanical energy. The stack will be fitted with diversion damper to direct the gas either to the heat recovery system or to the exhaust in case the heat recovery is down for maintenance without disturbing gas compression. The loss of power output from the Turbine to the Compressor shaft is negligible, only of the order of 1 to 2 %. With the implementation of this technology, the Company can ultimately recover about 300 MW of electrical power with no additional fuel. This is a very big monetary gain, around 40 million dollars per annum. It also provides an environmental edge because this energy is obtained with absolutely no emission. At current electrical energy rates, the capital cost can be recovered in very short time. It will also give the Company all the advantages of having its own power for its development needs without depending on external agencies.
One of the most promising Enhanced Oil Recovery (EOR) methods is CO2 injection. However, if the oil contains asphaltenes, CO2 injection may cause asphaltene precipitation and introduce production related challenges. Conventional three-phase (gas/oil/water) compositional simulators are unable to predict precipitation of asphaltenes and multiphase compositional simulators are required. The use of detailed multiphase equilibrium calculations is very CPU intensive and commercial simulation packages often employ a hybrid model that may not capture the true physics at play. Conflicting findings have been reported from experimental and theoretical studies: Some studies show that Asphaltene deposition, due to CO2 injection, takes place near the injection well, while others have reported that asphaltene deposition occurs near the production well. True multiphase equilibrium calculations can be used to demonstrate that both findings are possible and that many factors will affect the deposition behavior. Accordingly, a general statement such as CO2 injection causes more asphaltene precipitation relative to hydrocarbon (HC) gas injection is not always true. This added complexity indicates the need for multiphase compositional simulation to delineate asphaltene deposition behavior and quantity. In this work, we propose a four-phase compositional simulator (gas/oil/asphaltene/water) to predict the asphaltene precipitation during CO2 and HC gas injection processes. A new hybrid formulation, based on a simple table look-up approach, is introduced to replace detailed multiphase calculations (gas/oil/asphaltene) at a CPU requirement that is comparable to two-phase (gas/oil) equilibrium calculations. A range of simulation models/scenarios are presented to test and validate the new formulation against detailed multiphase compositional simulation, and we demonstrate an excellent agreement between the hybrid model and the full multiphase calculations. The proposed approach is easy to implement in commercial tools and provides a path to allow for more detailed studies of asphaltene precipitation and related production challenges.
All good equipment & system designs include certain margins to deliver operational flexibility, mechanical integrity and high availability under unforeseen variations in operating conditions. However, the adequacy & veracity of these margins has long been an issue of discussion. Project facility design goes through many cycles of reviews & updating during which, margins are added resulting in equipment or facilities that are difficult and expensive to operate & maintain. Reasons for over-design include working in silos, incorrect input-data, inappropriate simulation correlations and/or assumptions, non-linear incremental cost for upsizing, large project-cycle-time, lack of precedence, avoiding penalties etc. and last but not least, regional culture. This paper discusses the problems & root-causes associated with over-design, its evolution through various project stages & possible opportunities to limit over-design in up-stream oil & gas industry through real-life examples. This philosophy was utilized in recent projects and led to capex & opex savings besides delivering technically efficient systems. As majority of over-design cases relate to green-field projects, brown-field projects will not be discussed. Though over-design bias & its pitfalls apply globally to all sectors of the oil & gas industry, discussion will be focused around surface gas handling facilities (compressors mainly & brief references to pipelines, gas treatment units).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.