Petroleum and natural gas industries. Control and mitigation of fires and explosions on offshore production installations. Requirements and guidelines

1999 ◽  
Keyword(s):  
Natural Gas ◽  
Offshore Production

Water Equilibrium in the Dehydration of Natural Gas With Triethylene Glycol

1973 ◽  
Vol 13 (05) ◽  
pp. 297-306 ◽  
Author(s):  
A. Rosman
Keyword(s):  
Natural Gas ◽  
Water Content ◽  
Triethylene Glycol ◽  
Dew Point ◽  
Plant Performance ◽  
Water Removal ◽  
Dewpoint Temperature ◽  
Offshore Production ◽  
Lower Temperature ◽  
Offshore Production Platforms

Abstract To develop reliable design data for glycol contactors, gas-liquid equilibria in the system water-methane-triethylene glycol (TEG) were investigated experimentally. Equilibrium values vary little at the very high TEG concentrations used in modern contactor design, but increase significantly with increasing water concentration in the contacting TEG, and with increasing equilibrium temperature. Various methods of data correlation are described and compared with experimental data. The correlation provides the means for extending the results of this investigation to other pressures and temperatures. Introduction Water removal is a fundamental operation in natural gas processing. Hydrate formation, corrosion, and the formation of liquid water that might separate in the transmission lines are some of the problems caused by an excess of water in the gas. Of the methods available for gas dehydration, water absorption is by far the most generally used. Glycols, especially triethylene glycol (TEG), are the preferred absorbents. A survey of the literature on the water dew point of natural gas over glycol solutions reveals point of natural gas over glycol solutions reveals significant disagreements. A sampling of published dewpoint data for gas in equilibrium with TEG (Fig. 7) illustrates the prevailing confusion. Scant, but still contradictory, information was published for glycol concentrations in excess of 99.8 weight percent. Data in that range are needed in designing percent. Data in that range are needed in designing modern glycol contactors where the water dewpoint temperature must be reduced by more than 100 deg. F. The main reason for discrepancies in experimental results is the difficulty of measuring accurately very small amounts of water in gas. Water is easily adsorbed on the surfaces of experimental apparatus. Normally acceptable data scatter looms large in relation to the low water concentrations that must be measured. Attempts to establish water dew points on the basis of plant performance have been points on the basis of plant performance have been more successful. However, accuracy is limited by the difficulty in establishing the relative contribution of various factors that interrelate in plant operation. plant operation. Faced with these doubts, contactor designers have chosen to provide for TEG circulation rates that are overly high so as to insure more than adequate water removal. Such a practice is undesirable, however, where space and power are at a premium, as on offshore production platforms. Thus, the range of this investigation was governed by the need to extend equilibrium information to the contact temperatures and TEG concentrations necessary m optimize glycol contactors on offshore production platforms. production platforms. New procedures were developed for sampling and analyzing very small concentrations of water in gas and in TEG. To avoid experimental difficulties encountered by previous authors, equilibrium was reached and samples were taken under dynamic conditions. Experimental equilibrium results were smoothed and correlated by several methods. Thermodynamic equations were used to check on the internal consistency of data and to calculate equilibrium constants at conditions outside the range of the investigation itself. The White expression, fitted to the COFRC experimental data, adequately describes the results within the range of temperatures and concentrations studied. DEFINITIONS AND METHODS At water dewpoint temperature, the water contained in a natural gas reaches saturation. Part of that water will condense if the gas is brought to a lower temperature or to a higher pressure. Thus, the "dewpoint temperature" describes the water content of the gas. When dewpoint gas contacts TEG, the water content of the gas decreases. The lower water content corresponds to saturation water at a lower temperature; that is, the dew point will be lower. The initial dewpoint temperature is the contacting temperature. The temperature corresponding to the lowered water content is the equilibrium dewpoint temperature, and the difference between the two temperatures is the dewpoint depression. SPEJ P. 297

scholarly journals Rekayasa Nilai Kriteria Desain Fasilitas Produksi Gas Alam

2021 ◽  
Vol 6 (2) ◽  
pp. 120-134
Author(s):  
Hibrah Hibrah ◽  
Sutrasno Kartohardjono ◽  
Mohammed Ali Berawi
Keyword(s):  
Natural Gas ◽  
Net Present Value ◽  
Capital Expenditure ◽  
Hydrocarbon Composition ◽  
Comparison Method ◽  
Gas Production ◽  
Design Criterion ◽  
Production Unit ◽  
The North ◽  
Offshore Production

Natural gas is one of the primary hydrocarbon energies in Indonesia. The construction of natural gas production facilities is essential to accommodate domestic energy needs. These facilities include production, pipelines, and processing facilities in an integrated manner. This study used the hydrocarbon composition of Field-X with an average of 7.62% CO2 and 0.06% H2S. The alternative design uses a fixed platform (fixed platform), MOPU (Mobile Offshore Production Unit), and a Semi-Submersible platform. The design comparison criteria are capital expenditure (CapEx), net present value (NPV), internal rate of return (IRR), work completion time, safety risk, and flexibility of future facility development. Through the comparison method, it is found that Option A is the best option, which has a design criterion value of 57%, a higher NPV of $43,537,469.58 than the smallest NPV option, an IRR of 19%, and a payout time (POT) of 5 years. Option A uses a fixed platform with a pipeline to the north, the hydrocarbon separation process is carried out on an offshore platform, and the processing is carried out onshore. ABSTRAKGas alam merupakan salah satu energi hidrokarbon utama di Indonesia. Pembangunan fasilitas produksinya sangat penting untuk mengakomodasi kebutuhan energi dalam negeri. Fasilitas ini meliputi produksi, jalur pemipaan, dan fasilitas pengolahan hidrokarbon secara terintegrasi. Penelitian ini menggunakan komposisi hidrokarbon dari Lapangan-X dengan rata-rata CO2 7.62% dan H2S 0.06%. Alternatif desain menggunakan anjungan tetap (fix platform), MOPU (Mobile Offshore Production Unit), dan anjungan Semi-Submersible. Kriteria perbandingan desain adalah modal awal, nilai bersih saat ini (NPV), tingkat pengembalian internal (IRR), waktu penyelesaian pekerjaan, resiko keselamatan, dan flexibilitas pengembangan fasilitas kedepan. Melalui metode perbandingan yang dipadankan didapatkan Opsi A  adalah opsi terbaik, yang memiliki nilai kriteria desain 57%, NPV lebih tinggi $43,537,469.58 dibanding opsi NPV terkecil, IRR 19% dan waktu pembayaran (payout time/POT) 5 tahun. Opsi A  menggunakan anjungan tetap dengan jalur pemipaan ke arah Utara, proses separasi hidrokarbon dilakukan pada anjungan lepas pantai (offshore) dan pengolahannya dilakukan di darat (onshore). 

Process Design for the Offshore Production of Liquefied Natural Gas with Nonflammable Refrigerants

2015 ◽  
Vol 54 (44) ◽  
pp. 11106-11112 ◽  
Author(s):  
Chul-Jin Lee ◽  
Kiwook Song ◽  
Seolin Shin ◽  
Youngsub Lim ◽  
Chonghun Han
Keyword(s):  
Natural Gas ◽  
Process Design ◽  
Liquefied Natural Gas ◽  
Offshore Production

Numerical Simulation of Hydrate Transport in Natural Gas Pipeline

1998 ◽  
Vol 120 (1) ◽  
pp. 20-26 ◽  
Author(s):  
S. O. Ibraheem ◽  
M. A. Adewumi ◽  
J. L. Savidge
Keyword(s):  
Natural Gas ◽  
Fluid Model ◽  
Hydrate Formation ◽  
Higher Order ◽  
Solid Particles ◽  
Natural Gas Pipelines ◽  
Natural Gas Pipeline ◽  
Offshore Production ◽  
Two Fluid Model ◽  
Viable Approach

Accurate modeling of hydrate transportation in natural gas pipelines is becoming increasingly important in the design and operation of offshore production facilities. The dynamics involved in the formation of hydrate particles and in its transportation are governed by the multiphase hydrodynamics equations ensuing from the balance of mass, momentum, and energy. In this study, a two-fluid model is solved to characterize particulate transportation. The numerical algorithm employed is stable and robust and it is based on higher-order schemes. This is necessary since the governing equations describing the simultaneous flow of gas and solid particles are hyperbolic and, thus, admit discontinuities. Specialized higher-order schemes provide a viable approach for efficient frontal tracking of continuity waves in particular. Several simulation experiments that can facilitate thorough understanding of the design and maintenance of pipelines susceptible to hydrate formation are presented.

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