Territorija Neftegas № 4 2014
Read in this issue:
» Development of standard base for the increase of quantity determination reliability of produced crude oilOpen PDF
In order to increase the reliability of quantity determination of produced crude oil, works have been conducted on the development of State primary special standard of oil and oil products volumetric water content unit. The new standard GET 87-2011with improved metrological characteristics provides reproduction of oil-water mixture volumetric water content unit within the range of (0.01÷99.9%).
Keywords: oil; water content; standard; metrological characteristics.
» Analysis of the calculation methods of foundations under gas pumping units at compressor plants in complicated geological conditionsOpen PDF
The article includes benchmarking of the existing methods of dynamic analysis of foundations under gas pumping units (GPU). Main theories of construction standards for calculation and design of foundations under GPU are studied. The improved model of soil foundation that enables to take into account strong non-homogeneity of the soil foundation was developed. The improved model enables to forecast any emergencies related to melting of frozen ground. Change of foundations vibration during GPU operation was analyzed taking into account change of frozen ground stiffness as a result of its seasonal melting and freezing cycles, as well as possible emergencies related to high heat emission.
Keywords: gas pumping unit (GPU), foundation, soil foundation, frozen ground, rotor rpm, dynamic loads, vibration amplitudes, stiff resistance of the foundation, damping, emergencies.
Fields facilities installation
» Risk oriented strategy for managing integrity of oil and gas fields surface infrastructureOpen PDF
This article completes the series of publications in Nos. 9–12 for 2013 and No. 3 for 2014 of NEFTEGAS Territory journal dedicated to managing the integrity (IM) of oil and gas fields infrastructure. The previous articles contained description of the life cycle stages of the oil and gas fields infrastructure, IM was defined for the stage of the infrastructure facilities operation. The key performance indicators of infrastructure maintenance costs were proposed, showing that the major line of the IM performance management is the identification, assessment and prioritization of risk associated with breach of integrity. Based on the risk oriented approach the principles of cost formation and optimization using the standard are described. As exemplified by the pipeline infrastructure, practical possibility of risks identification, assessment and prioritization is shown, which is based on the analysis of the public information on the operated facilities. Besides, the possibility of risk assessment is shown for complex infrastructure facilities of oil and gas fields as well, using unified system of risk assessment and elements of identifying potential interrelated adverse events associated with major risks. However, the preceding publications of the series do not answer the questions, which arise when managing the integrity of complex multi-functional production facilities or assets within a large holding, when encountering such problems as selecting the priority of financing to maintain the infrastructure among facilities of various nature, optimizing costs in a short and long term. This article describes the IM elements and strategies required for the entire surface infrastructure facilities complex of oil and gas fields, ensuring both risk management and maximum economic efficiency. For managers and petroleum engineers engaged in design and operation of surface oil field and other infrastructure facilities, specialists in the area of risk assessment, industrial safety and environmental protection, assets feasibility study.
Keywords: risk assessment, strategy, integrity management, accident rate, pipelines, oil.
» Features of gas condensate well testsOpen PDF
Here is a research of pressure behavior features during gas condensate well tests, specific properties of build-up curves of wells of Urengoy field achim deposit are analazied.
Keywords: well tests; build-up analyzes; gas condensate wells.
» Development of the automation system mathematical model for the sucker rod pump electric driveOpen PDF
This paper deals with the method for enhancing the sucker rod pump (SRP) efficiency on the basis of the frequency converter (FC) with pulse-duration modulation (PDM). It contains the development of the SRP electric drive mathematical model facilitating the research into the transition processes of the dynamic system startup, including mains, transformer, cable, induction motor (IM), SRP. This paper also elaborates the equivalent circuit of the plant in question and also its mathematical description both under direct startup and the IM start up from the frequency converter with pulse-duration modulation. Graphs of current, angular speed, electromagnetic torque depending on the time and subject to the dynamic load borne by the electric motor shaft are obtained.
Keywords: modeling, energy efficiency, electric drive, sucker rod pump, deep well pump, frequency converter with pulse-duration modulation, induction electric motor.
Transport, storage and processing of oil and gas
» Expertise of gas leaks from the gas pipelines with high pressureOpen PDF
The question of calculating gas losses out of gas pipelines containing gas under high (5-15 MPa) or ultra-high (20-35 MPa) pressures is studied in this paper. The classical theory of this question gives answers about regimes of gas outflow, about pressure, temperature, density and velocity of the gas outflow, as well as about the gas flow rate, however, this theory assumes that the gas is perfect one (i.e., gas properties are described by the equation of state of Mendeleev-Clapeyron ). It is also assumed that the internal energy and enthalpy of the gas depend only on temperature, process is considered as adiabatic one, described by the classical Poisson adiabat. For real gas in gas pipelines with the high pressure, most of these assumptions do not hold, and although the efflux of the gas really is adiabatic, nevertheless equation of the adiabat is completely different from the same equation in the classical case. As a result the other value of gas loss is also obtained. The paper proposes a decision of this question, free from unwarranted assumptions.
Keywords: calculation, leak, gas loss, gas pipeline, high and ultra-high pressure, critical mode of gas outflow, real and perfect gas, the equation of state, the Joule-Thomson effect, adiabatic process, the heat capacity, adiabat of real gas.
» Comparative analysis of the use the safety valve and the gas cap as systems of protection against hydraulic shock of the marine oil terminalOpen PDF
Methodology of evaluation of parameters of gas caps, which used as protection systems from the water hammer of the marine oil terminals, was proposed. It is shown that due to the large size of the gas caps of their use as a system of protection against hydraulic shock is appropriate only for short liquid pipelines of small diameters and low productivity of loading of ships. Unlike the safety valve, which limited the pressure in the pipeline at the level of the set pressure, the level of increase of pressure in a gas cap in the hydraulic impact depends on the selection of its original volume. Underestimation of any of the numerous localities of factors influencing the required volume of gas cap, especially when you try to minimize its size, will inevitably lead to the accident, the spills of oil into the marine waters of the port.
Keywords: marine oil terminal, hydraulic shock, water hummer, surge relief system, protective system, pipeline safety valves, gas cap, loading pipeline.
Pipelines operation and maintenance
» Research of influence of the form central and lateral gas-intake on uniformity the liquid piston of pump-compressor installationsOpen PDF
Results of research of influence of the form central and lateral gas-intake on uniformity the liquid piston are presented at work experimental pump-compressor installations. Optimum forms gas-intake by criterion uniformity and the maximum rapidity of installation are defined.
Keywords: pump-compressor installation, liquid piston, uniformity, gas-intake.
» Estimate of the pipeline stress in the underwater crossing section after gas depressurizationOpen PDF
Residual stress in the pipeline of the underwater crossing after gas depressurization has been studied. Values of these stresses were estimated for local sections of the pipeline. It was shown that the residual stress give an additional contribution to the actual longitudinal stress of the pipeline and to its displacements under operation of the underwater crossing.
Keywords: pipeline, underwater crossing, stress-deformed state, transverse displacement of a pipeline.
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