Among the main objectives of Pemex Exploracion and Produccion Region Sur is found the analysis of the operation, the optimizacion and the modernization of the systems of produccion, transportation and distribution of hydrocarbons, in order to provide better security conditions, efficiency and opportunity, without forgetting the proteccion to the environment and the society. For the foregoing, it results from great importance to count on a methodology for planning the behavior and development of the infrastructure of produccion and transportation to face current and future needs, bearing in mind the operational requirements and quality that demand best engineering practices. The utilization of Process and Transport Simulators to analyze the facilities in the current operation conditions, and to predict their behavior under different stages is a valuable tool that applied combined with the best practices of engineering allows to predict, with meaningful time savings, the necessary modifications to be adjusted to the new operative philosophy, without putting on risk the facilities. As added value, the results obtained from the application of this methodology also contributes to the construction of a data base, of the facilities of produccion as well of transportation, of great usefulness for activities related to the maintenance programs.
SPE 59029 Design and Development of Hydrocarbon Surface Production Facilities and Pipelines Based on Process And Transport Simulators M.P Castillo, SPE, Instituto Mexicano del Petroleo; M Murillo, Pemex Exploracion and Produccion Region Sur,and C Cabrales, Instituto Mexicano del Petroleo Copyright 2000, Society of Petroleum Engineers Inc This paper was prepared for presentation at the 2000 SPE International Petroleum Conference and Exhibition in Mexico held in Villahermosa, Mexico, 1–3 February 2000 This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s) Contents of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s) The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the Society of Petroleum Engineers is prohibited Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented Write Librarian, SPE, P.O Box 833836, Richardson, TX 75083-3836, U.S.A., fax 01-972-952-9435 Summary Among the main objectives of Pemex Exploracion and Produccion Region Sur is found the analysis of the operation, the optimizacion and the modernization of the systems of produccion, transportation and distribution of hydrocarbons, in order to provide better security conditions, efficiency and opportunity, without forgetting the proteccion to the environment and the society For the foregoing, it results from great importance to count on a methodology for planning the behavior and development of the infrastructure of produccion and transportation to face current and future needs, bearing in mind the operational requirements and quality that demand best engineering practices The utilization of Process and Transport Simulators to analyze the facilities in the current operation conditions, and to predict their behavior under different stages is a valuable tool that applied combined with the best practices of engineering allows to predict, with meaningful time savings, the necessary modifications to be adjusted to the new operative philosophy, without putting on risk the facilities As added value, the results obtained from the application of this methodology also contributes to the construction of a data base, of the facilities of produccion as well of transportation, of great usefulness for activities related to the maintenance programs The results of modeling are completed with an economical analysis in order to find the best alternative to solve a particular situation The obtained information is documented and ordered to justify the new projects and the required investments Introduction The Region Sur has an importance of first order in the context of the economics and the national politics From the fiftys the states of Tabasco, North of Chiapas and Veracruz began to receive strong investments that sponsored the takeoff of this zone as international trade pole in base to three factors: • • • Their geographic location that connects them with large three ports (Dos Bocas, Pajaritos and Salina Cruz) The great industrial development achieved in the other subsidiaries of Pemex (Pemex Refinacion, Pemex Gas y Petroquimica Basica and Pemex Petroquimica) The quality of the hydrocarbons, what permits to improve the crude mixtures for exportation as well as for the processing at domestic level In general terms the Region Sur is characterized by generating 20 percent of national produccion of oil, 46 percent of the produccion of the gas, and 16.6 percent of gas liquids Currently the produccion of gas in the region is of 190 mmpcd in average Of this volume 86 percent originates of the Mesozoic and 14 percent of the Tertiary Concerning to gas liquids the produccion is of 14 725 bpd of which 96 percent corresponds to the mesozoico and percent to the Tertiary The gas and condensate produced have as final destination the processing gas centers of Cactus, Nuevo Pemex, Cd Pemex and La Venta It is convenient to indicate that the Region Sur receives part from the gas from the Marine Region by Atasta for its processing in Cd Pemex, Cactus and Nuevo Pemex In general terms the gas and the condensate that are transported in the Region Sur are sour and saturated with water, what implies a greater duct and equipment deterioration due to corrosion On the other hand, part of the infrastructure could be in the limit of its operative life, therefore to prevent any further risk is necessary the substitution of some components 2 M CASTILLO, M MURILLO, C CABRALES Additionally, the produccion of gas and of condensate tends to reduce, therefore in some instances it must be considered the sustitution, relocation or modification of the infrastructure, or even to propose different alternatives of operation Based on all of the above a team of engineers carried out the modelation of the systems, particularly concerning the managing of the gas and the condensates in the Region Sur This modelation has the purpouse of detecting bottle necks in the current infrastructure, and to optimize transportation systems to face future demands Description of Process and Transport Simulators In the market exists a great variety of simulators that have proven their usefulness in oil industry, particularly with respect to optimize nets of ducts and facilities for hydrocarbon processing Modeling Procedure In figures and are shown the Produccion and Transportation Systems, from which we began construction of the models These figures indicate the way the produccion of gas and condensated, originated from the different facilities is gathered, and the physical characteristics of the available pipelines Finally these volumes of hydrocarbons are delivered to the processing gas centers of Cactus, Nuevo Pemex and Cd Pemex In agreement with the authorities of Pemex Exploracion and Produccion, the Instituto Mexicano del Petroleo began the process of modeling with the following objectives: • • In figure are shown the computer programs that were used an their capacity to reproduce and predict the necessary operation conditions for the design of produccion and transportation systems These simulators were selected in base to the obtained experiences from their application, that is to say the accuracy to reproduce the operation conditions as obtained from the field Concerning what is referred to the quality and type of informacion fed to the models we can say that this is of three types: the obtained from the instruments installed in field (Pressure, Temperature and Flow); the mechanical characteristics of the system (Diameter, Length, Thickness, Material of Contruction, Right of Way and Topographic Profile); and the Compositional Analysis of the Hydrocarbons (C1 to C6+, CO2, N2, H2S and water content) On the other hand, it is also mandatory to know the produccion forecasts required to evaluate the systems under different operative stages, and the information obtained from calibrating pigs which provides data on the current situacion of the thickness of the pipeline, crucial information to establish the maximum operating pressure of the pipe, that is pressure for transport Characterization of fluids This factor is a key factor for the design and development of Production and Transportation facilities, since the results that are obtained as product from modeling are found intimamente related to the composition of the fluids processed For the case of the hydrocarbons processed in production facilities the information of the - PVT Analysis- obtained from reservoir samples is used With respect to gas transportation, cromatographic analysis is been used SPE 59029 • • To reproduce the behavior of the transportation systems, particularly with respect to the cases of two phase flow in which "Retrograde Condensation” phenomena takes place To analyze in transportation nets the effect by incorporating greater volumes of hydrocarbons, or decline of the produccion To detect possible bottle necks To accomplish overall sensibility studies (Technical and Economical) of the operation of the system Hydrocarbons Characterization In spite of the fact that the characteristics of the products obtained in a production unit depend on the compositional analisis of each one on the wells that flow to this, by the difficulty that represents the availability of recent samples, a discrimination of the existing informacion is adopted and, as of the Analisis - PVT - available, through the use of simulators was obtained the necessary characterization for the modeling However, in some instances before the absence of exact information “Black oil” option has ben taken In figure is presented an example of the data treatment that is effected to a Sample - PVT - of a well to obtain the corresponding compositional analisis With respect to the transported gas, the chromatographic analisis is preferred the one that routinely is performed in production facilities The experience has demonstrated the usefulness that represents the power to determine with the greater possible accuracy the heavy ends, since they influence accuracy in prediction of condensacion during transportation, as well as the identification of undesirable flow patherns In the table is shown a typical example of gas composicion obtained in the region Due to the difficulty to determine the concentration of water in the gas streams produced in production facilities, it is been adopted, with good results, to determine this concentracion as of the operation conditions and the composition of the hydrocarbons, applying equations of state (Peng-Robinson and Soave-Redlich-Kwong) The accuracy of this SPE 59029 DESIGN AND DEVELOPMENT OF HYDROCARBON SURFACE PRODUCTION FACILITIES AND PIPELINES BASED ON SIMULATOR consideration has been corroborated comparing the obtained results from the modeling against information of field in those points where water could be measured in liquid form Required Information and Design Criteria The simulators are capable of modeling production and gathering systems, including within these parallel pipelines or "Loops" • However, in our case, in the one which the systems are existing; that they began their operation in different conditions from the current; and that in the future is possible that they have to comply with different operation conditions, these recommendations have been considered as a reference, and the projects accomplished in the Region Sur have developed their own criteria These simulators report composition of phases, pressure drop, liquid formation or "Hold Up", flow patterns , transportation velocity, and thermophysical properties of the fluids involved in the design of the equipment To get this data the following informacion is fed: • • • Composition.- Such as we mention before, for high molecular weight streams this is obtained from data treatment from the - PVT Analisis - to obtain the concentration of identificable components asi well as pseudocomponents In the case of the gas streams, light molecular weight, chromatographic analysis is used directly Pressure, Temperature and Flow.- This information is obtained from operating logs In those cases when is intended to operate at different conditions of the current, is agreed with the operator the range in which these variables can be modified so that, during the stage of modelacion of stages, are analyzed only those feasible cases to be carried in practice Calculation Methods.- The experience obtained throughout several years devoted to the modelation of production facilities has carried us to use, for the calculation of gas-liquid equilibria, thermophisical properties,Peng Robinson, Soave-Redlich-Kwong, LeeKessler, Grayson Streed In regard to the viscosity, it has been proven that the utilization of experimental viscosities for heavy fractions is highly advisable In what concerns to the multiphase transport, horizontal or vertical , it has been used Taitel-Dukler-Barnea, Beggs and Brill, Dukler-Edton-Flanigan • Process Equipment and Right of Way.-In this case it is provided the informacion related to the size of the equipment, the internal diameter, length and topographic profile of the pipeline • On the other hand, taking into account the characteristics of the right of way, our experience recommends to use overall heat transfer coefficients “U” of 1.20 and 0.66 BTU HR FT² ºF/FT for gas and liquid transportation respectively Fluid Flow.- There are several field studies that recommend velocities to design pipelines In most of the cases this recommendations seek to avoid, through the control of the velocity, erosion, stratificaction of water or solids, and undesirable flow patherns As a reference we could mention for gas 20-60 FPS and for liquids 4-10 FPS • Flow Patterns.- As a rule it is considered to avoid undesirable flow patterns such as "Slug" and "Plug" However you dont’n have to forget that in the case of the transportation of the associated gas the phenomena of "retrograde condensation" which leads to multifhase flow, the alternative to control the volume transported to avoid these patterns could be identified in the field by the fluctuacion of the operation conditions in the delivery points at the end of pipe • Validation of the Model.- Once it is fed all the information to the model, a series of runs in the computer are performed which main objective is to reproduce, as close as possible, from the operation conditions of the system in the origin, the conditions in the extreme of the duct These final conditions commonly are: volumes of liquid and gas, pressure and temperature, volumes of liquids displaced by pigs, etc • Operational Philosophy and Production Forecasts.Such as we mention before, in order to establish if a system has the necessary operative flexibility, it is important to count on with the production forecasts This document contains the yearly produccion of hydrocarbons during a period of at least 15 years, and upon using it we will be able to know to identify bottle necks in the system and then to find out the operative or constructive alternatives to avoid them Modeling of Gas Gathering System “CatedralMuspac-Chiapas-Giraldas-Cactus” Catedral-Muspac.Chiapas-Giraldas-Cactus System is a high pressure pipeline network which gathers associated gas obtained in four production units The total amount of gas is M CASTILLO, M MURILLO, C CABRALES delivered at high pressure to be processed in a Gas Processing Plant located in Cactus Figure shows the results obtained when we apply the methodology for a high pressure sour gas gathering system This figure presents a comparison between operating conditions and those values obtained by simulation As we can see deviation in the majority of cases remains in aceptable level, therefore the model is validated Figure shows the proposed infraestructure required to operate the same system but at lower pressure including some other separation units Conclusions The use of processing and transportation simulators has been of great help to analyze, eliminate bottle necks and to optimize the current and future facilities for the managing of gas and condensate in the Region Sur The decisionmaking to change the philosophy of operation of the facilities, or to justify the construccion of new infrastructure, preserving the security margins recommended to protect the environment and population, avoiding the deferred produccion, is facilitated with the employment of the simulators without putting on risk the infrastructure It is been proved the usefulness that represents countting on recent compotional analysis However it is advisable to detect as much as possible high molecular fractions in the chromatograph The resource of using a - PVT anlysis - or the option "Black Oil" leads to greater deviations and alone are recommended as the last resource, or for very general studies to explore alternatives of operation The aplicacion of simulators to plan the development of the processing infrastructure, with sufficient flexibility to fulfil future requirements, requires of reliable information the one which is obtained from an adequate and calibrated instrumentation in the field The routine use of simulators for the design of processing and transportation facilities of hydrocarbons allows the optimization of the infrastructure making it efficient and adjusted to the requirements of Pemex Exploracion and Produccion Region Sur Nowadays IMP is working in an integral model which considers the total network of gas an liquids pipelines in Region Sur This tool when completed could facilitate estimation of produccion delivered to gas processing plants, predict operating conditions required to cope with the missoperation of a pipeline or failure, and detect best SPE 59029 alternatives to handle hydrocarbons within the gathering network Nomenclature MMSCPD=Million standard cubic feet per day BPD= Barrels per day FPS=Feet per second P=Pressure, kg/cm² T=Temperature, ºC CPG= Gas Processing Plant References John Campbell: Gas Conditioning and Processing Vol I J McHugh:On Target with Rough Gas Engineering and Management Gas Processors Suppliers Asociation:Engineering Data Book, 1972 Word Rosen: Gas Processing,1996 O W Boyd: Petroleum Fluid Flow Systems, 1983 A Minkkenen: Make Best use of Associated Gas,1981 Norma No 07.3.13, PEP 171,Requisitos Minimos de Seguridad para el Diso, Construccion, Operación, Mantenimiento e Inspeccion de Tuberias de Transporte, 6ª Revision, Septiembre 1994 PEMEX FA-2716: Evaluacion de los Sistemas de Recoleccion, Transporte y Distribucion de Hidrocarburos en la Region Sur 1997 PEMEX P-1008: Analisis Tecnico Economico de Opciones de Proceso, Transporte y Entrega de Gas y Condensado en la Coordinacion Tecnica Operativa.1999 SPE 59029 DESIGN AND DEVELOPMENT OF HYDROCARBON SURFACE PRODUCTION FACILITIES AND PIPELINES BASED ON SIMULATOR COMPONENT MOL % N2 1.151 CO2 2.528 H2S 4.656 C1 73.683 C2 10.276 C3 4.375 IC4 0.696 NC4 1.343 IC5 0.421 NC5 0.431 C6+ 0.441 PRESSURE 85 KG/CM2 TEMPERATURE 50 °C MOLECULAR WEIGHT (GR/GR MOL) 22.253 SPECIFIC GRAVITY (AIR=1) 0.768 DENSITY (LBS/M3) 2.075 PROPANE PLUS (BLS/MMPCD) 53.689 CP GROSS (KCAL/M3) 9951.02 CP GROSS (BTU/FT3) 1118.21 TABLE TYPICAL GAS COMPOSITION PROCESS HYSYS PRO II ASPEN PLUS SIMPROC INPUT TRANSPORT PIPEPHASE PIPESIM-NET PIPEFLOW LINEAS II OUTPUT GAS-LIQUID EQUILIBRIUM FLOW COMPOSITION TEMPERATURE PRESSURE HEAT TRANSFER “U” DESIRED FLOW PATTERN TOPOGRAPHIC PROFILE PRESSURE DROP THERMOPHYSICAL PROPERTIES FLOW PATTERN OPERATING CONDITIONS ALONG THE PIPELINE RETROGRADE CONDENSATION RIGHT OF WAY FIGURE COMMERCIAL SIMULATORS 16 "Ø MUSPAC x6 x6 KM 12 "Ø TECOMINOACAN KM CATEDRAL KM x 9 36" KM x 9 24" JUJO 16" x 13 KM x 24" x 15.7 KM 36" GIRALDAS 15.7 KM 24" x 10 K M 36" x 21 K M 24" x 11 K M 36 34 "x M T.R.D M AREA DE TRAMPAS OXIACAQUE SITIO GRANDE 30" x KM CACTUS-IV 10" x 5.5 KM CACTUS I 24" x 4.7 KM 36" x 10.5 KM CACTUS-II 24" x 79 KM 36" x 14.8 KM 36" x 10.5 KM 36" x 30.8 KM 30" x 2.8 KM 24" x 9.8 KM KM 77 "x C.P.G CACTUS AREA CACTUS IV SUNUAPA KM AREA NORESTE SAMARIA-II 36 KM 24" x 5.97 KM 16" x 5.97 KM SEN PROVISIONAL FIGURE GAS GATHERING SYSTEM PRESENT AND FUTURE CHIAPAS OPERA EN P.I REQUERIMIENTO EN A.P KM 16 "x 12" x 6.46 KM PAREDON BELLOTA OPERA EN P.I REQUERIMIENTO EN A.P CARDENAS NORTE DOS BOCAS 16" x 14.4 KM 16" x 21 KM BAT COMPRESORAS CUNDUACAN SL U G6 " x CAT 14 CH ER KM 16" x 10 KM KM x9 LUNA 37 KM 36" x KM AGAVE EXISTING PIPELINES PIPELINES IN CONSTRUCCION PIPELINES IN PLANNING 30" x ATASTA C.P.G CD PEMEX PIJIJE C.P.G NUEVO PEMEX AREA NUEVO PEMEX 16" x 0.1 KM 20 " 36" x 56.5 KM 16" x 10 KM 24" x 7.1 KM KM 4.7 x1 36 " 24"Ø x 34 KM KM 65 24"Ø x 13 KM 36" L-2 x 92 KM 36" L-3 x 92 KM 36" x 70 KM "x 36 36" x KM 24" x 0.5 KM 12" x 8.5 KM M CASTILLO, M MURILLO, C CABRALES SPE 59029 TECOMINOACAN 8" X 6.5 KM 8" x 15 K M O X JUJO 8" 14 KM 8" GIRALDAS PAREDON 10 KM 1.8 (1) "X2 KM SUNUAPA 8" X1 0K M KM M 11 K 8" X X 14 4.9 KM SAMARIA-III BAT CACTUS I IT 8" X3 0K M RK PIP S A S EL A INE N O IL WO ENTRONQUE 6" X 4.8 KM OPERATION OUTSIDE COMP CACTUS I 8" X KM 6" X KM 6" X KM 16" X 10.5 KM 6" X 44 KM AGAVE CACTUS II 36" X 10.5 KM OPERATION OUTSIDE 6"X4.4 KM SAMARIA-II SLUG-CATCHER X SITIO GRANDE AREA CACTUS IV C.P.G CACTUS 12" KM 77 8" BAT Y COMP CUNDUACAN C.P.G NVO PEMEX AREA NUEVO PEMEX 24"X79KM SEN FIGURE CONDENSATE GATHERING SYSTEM PRESENT AND FUTURE CHIAPAS X 32 8" AREA NORESTE CABEZAL JUSPI 21 KM 20 KM 8" X 8" X BELLOTA 24" X 10 KM CARDENAS NORTE 8" X 15 KM KM 28 8" X KM X 8" 4" X 15 KM M 7.1 K 8" X 8"X8 K M C.P.G CD PEMEX 16" X 1.5 KM 16" X 91.5 KM PIPELINES IN PLANNING PIPELINES IN CONSTRUCCION EXISTING PIPE LINE 24" X 70 KM RECOMPRESION ATASTA SPE 59029 DESIGN AND DEVELOPMENT OF HYDROCARBON SURFACE PRODUCTION FACILITIES AND PIPELINES BASED ON SIMULATOR M CASTILLO, M MURILLO, C CABRALES SPE 59029 START RESERVOIR PVT ANALYSIS OPERATING CONDITIONS CHECK PROPERTIES AGAINST EXISTING DATA ON FIELD MODELING OF PRODUCTION FACILITIES RESULTS MATCH EXISTING INFORMATION IN THE FIELD ? (MOL %, GOR, ETC) NO YES COMPOSITION OK FOR FUTURE SIMULATIONS END FIGURE PVT ANALYSYS DATA TREATMENT MAKE ADJUSTENTS IN COMPOSITION Km X "B" X Km MUSPAC SECTION 36"ø M CHIAPAS "C" M M 36"ø X 21 Km SECTION X Km 13 X Km 13 "D" JUSPI 24"ø SLUG 36"ø - C.P.G CACTUS SECTION "C" SECTION "D" CHIAPAS ENVÍO GIRALDAS RECIBO GIRALDAS ENVIO CACTUS RECIBO F P T F P T F P T F P T 365 83.0 32.0 365 80.0 29.0 535 80.0 36.0 535 73.0 32.0 365 82.1 31.7 365 79.8 28.4 535 79.8 34.9 535 71.8 28.0 - -1.1 -0.9 - -0.3 -2.1 - -1.2 -3.1 - -1.6 -1.25 SECTION GIRALDAS N C SECTION "A" SECTION "B" CATEDRAL ENVÍO MUSPAC RECIBO MUSPAC ENVIO CHIAPAS RECIBO F P T F P T F P T F P T 120 90.0 57 120 85.0 50 330 85.0 54.0 330 84.0 50.0 120 90.2 57 120 84.1 46 330 84.1 50.6 330 82.8 46.2 - 0.2 - - -1.1 -8.0 - -1.1 -6.2 - -1.9 -7.6 SECTION 16"Ø CATEDRAL Km FIGURE HIGH PRESURE SOUR GAS GATHERING SYSTEM: CATEDRAL-MUSPAC-CHIAPAS-GIRALDAS-CPG CACTUS, VALIDATION OF MODEL (80-90 kg/cm2) FIEL DATA SIMULATION DESVIATION % "A" 9.9 M 36"ø 15.7 X SPE 59029 DESIGN AND DEVELOPMENT OF HYDROCARBON SURFACE PRODUCTION FACILITIES AND PIPELINES BASED ON SIMULATOR 9.9 16"Ø X CATEDRAL 36"ø M 13 24"ø X 9.9 Km 13 MUSPAC X Km M SUNUAPA 24"ø X 15.7 Km N C CHIAPAS 36"ø N C M GIRALDAS X X Km M 36"ø X 21 Km C.P.G CACTUS C.P.G CACTUS PROPOSED PIPELINE EXISTING PIPELINE CATCHER 24"ø X 34 Km JUSPI 24"ø SLUG - Km "ø FIGURE INTERMEDIATE PRESSURE SOUR GAS GATHERING SYSTEM: CATEDRAL-MUSPAC-CHIAPAS-GIRALDAS-CPG CACTUS, PROPOSED NEW PIPELINES (41-51 kg/cm2) X M 15.7 16"ø X 10 Km 10 M CASTILLO, M MURILLO, C CABRALES SPE 59029 ... composition of the hydrocarbons, applying equations of state (Peng-Robinson and Soave-Redlich-Kwong) The accuracy of this SPE 59029 DESIGN AND DEVELOPMENT OF HYDROCARBON SURFACE PRODUCTION FACILITIES. .. Entrega de Gas y Condensado en la Coordinacion Tecnica Operativa.1999 SPE 59029 DESIGN AND DEVELOPMENT OF HYDROCARBON SURFACE PRODUCTION FACILITIES AND PIPELINES BASED ON SIMULATOR COMPONENT MOL %... 91.5 KM PIPELINES IN PLANNING PIPELINES IN CONSTRUCCION EXISTING PIPE LINE 24" X 70 KM RECOMPRESION ATASTA SPE 59029 DESIGN AND DEVELOPMENT OF HYDROCARBON SURFACE PRODUCTION FACILITIES AND PIPELINES