Pdf understanding the behaviors of gas condensate reservoirs. Flow behavior of gascondensate wells stanford earth. This study addresses the monitoring of a realistic gas condensate reservoir by timelapse seismic data and transient well test analysis. Simulation model setup a compositional simulation was conducted to predict individual well performance. Introduction to reservoir simulation dr panteha ghahri.
Accuracy with which the geological description of the reservoir is matched discretisation of the flow equations heriot watt university, reservoir simulation. Gas gets out of solution, moves upward, forms a gas cap 2phase flow into the well bore, different mobilities, glr questionable cce dle cce cvd gas condensate gc. A compositional reservoir modelling is employed to perform the numerical well test simulation. A commercial simulator was then used to carry out numerical reservoir simulation of fluid flow in the north field. Developing an easytouse simulator to thermodynamic. Discretization and gridding in reservoir simulation 2. Once an accurate model was obtained, the following three solutions to. Traditional methods of sensitization during reservoir simulation for gas condensate fields creates the challenge of quick identification of the most critical properties for sensitization, and.
Reservoir simulation is the study of how fluids flow in a hydrocarbon reservoir when put under production conditions. Reservoir simulation models are commonly used to predict the performance of retrograde gascondensate reservoirs. N2 gascondensate reservoirs have been the subject of intensive research throughout the years as they represent an important class of the worlds hydrocarbon reserves. Gas condensate production may be thought of as a type intermediate between oil and gas. Pvt model followed by reservoir simulation studies. The first step of the study involved gathering north field reservoir data from previously published papers. Barnum brinkman fp, richardson rw spillette ag gas condensate reservoir afidick 12. The reservoir parameters screening were done with pareto chart select influential parameto ters.
The compositional case optionally uses tabular kvalues versus p. Ron terry discusses gas condensate reservoirs, calculating hydrocarbon in place. An earlier probabilistic assessment for the case study reservoir was built based primarily on core data from two analogous reservoirs, one of which was from the same field, prior to the availability of bottom hole pressure and drawdown data. During the production of a gas condensate reservoir, heavier hydrocarbon components in the gas drop out as liquid when the reservoir pressure declines below the fluid dew point pressure nagarajan et al. This project is a research into the effect of gas condensate damage in hydraulically fractured wells.
In gas condensate reservoirs, by reservoir depletion, pressure decreases below the dew point pressure of the fluid and condensate forms in the reservoir. A simulator is a program used to perform material balance calculations to determine pressure and saturation distribution of the reservoir as a function of time. A simulation study requires description of the reservoir s rock and fluid properties, validation of completion and production history, and extensive history matching to validate and modify this input data. Api and gor condensate fraction in surface separators reservoir conditions. Third spe comparative solution project, gas cycling of retrograde condensate reservoirs, paper no. Reservoir simulation models are commonly used to predict the performance of retrograde gas condensate reservoirs. Pdf optimization of condensate recovery using gas recycling.
Modeling and optimization of the rich gascondensate reservoir. The commonly used volumetric method involves defining areal extent of the reservoir, rock pore volume, and fluid content within the pore volume with applications of geophysics and well. Modelling the effect of composition change during condensate. Four reasons why your gas condensate fluid model is. There are various flow regions encountered in a gas condensate reservoir, along with the pressure profile and the liquid dropout. Gas condensate reservoirs are distinguished by producing both gas and condensate liquid at the surface. The constant compositional changes in the gas condensate reservoir, makes it a complex system, requiring compositional simulation to be able to model the phase behavior of the fluid and evaluate the recovery processes properly. Co2 enhanced gas recovery and geologic sequestration in. A dry gas reservoir is defined as producing a single composition of gas that is constant in the reservoir, wellbore, and leaseseparation equipment throughout the life of a field. Shift factors3 are included to account for volume translation.
Compositional modeling of gascondensate reservoirs. Gas condensate with immobile water simulation input file 77. Eclipse was now used to simulate under varied conditions to study the effects of relative permeability and critical condensate saturation on gas and condensate recovery. Based on known moles of gas and condensate, determine the fraction of produced gas and condensate in the reservoir fluid stream. This paper presents a genertilzed equation of state eos that represents several widely used cubic eoss. Formation of a condensate bank, in case of lean condensate immobile well stream composition reservoir composition rich condensate. According to the previous studies, the addition of some nitrogen causes a considerable increase in mixture dew. Optimal injection time and parametric study on gas condensate. It is assumed that a well is located at the midpoint of the gas reservoir, and the simulation parameters are shown in table 4. Reservoir simulation is an area of reservoir engineering that, combining physics, mathematics, and computer programming to a reservoir model allows the analysis and the prediction of the fluid behavior in the reservoir over time.
T1 optimized exploitation of gascondensate reservoirs using neurosimulation. General material balance for gas condensate reservoir and its. Kleinsteiber has over 24 years of petroleum engineering experience and has authored or coauthored papers dealing with production decline type curve analysis, co2 flooding, and depletion of a rich gas condensate reservoir by. A simulation study of the effects of injection pressure on condensate recovery from reservoir and co 2 storage efficiency jonathan narinesingha, david alexanderb a,bthe university of trinidad and tobago,esperanza road, brechin castle, point lisas, trinidad, west indies. The more recent models actually attempt a full dynamic integration.
Developing an easytouse simulator to thermodynamic design. A drygas reservoir is defined as producing a single composition of gas that is constant in the reservoir, wellbore, and leaseseparation equipment throughout the life of a field. Presently, gas condensate reservoirs experience reductions in productivity by as much as a factor of 10 due to the dropout of liquid close to the wellbore. Gas condensate reservoirs in niger delta and around the world are becoming increasingly important as a result of additional liquid recovery and increasing demand for light oil and natural gas. Accurate forecasting of gas condensate well productivity usually requires finegrid numerical simulation to model the formation of the condensate bank and to account for highvelocity phenomena. Coats, sw inteow resoue development and engiaring, inc. Optimized exploitation of gascondensate reservoirs using. Reservoir management fundamentals the reservoir management consists on the application, within a given fiscal and contractual frame, of wellestablished industrial technologies and field best practices to a hydrocarbon reservoir, in order to efficiently perform the field operations and maximize the economic return of the investments. The liquid is sometimes called by an older name distillate, and sometimes simply oil.
Ron terry discusses gas condensate reservoirs, calculating hydrocarbon in place using two methods. Application of compositional simulation in seismic modeling. Reservoir simulation applications vary at different stages of production life depending on the available data. Natural gas condensate aka gas condensate, condensate, natural gas liquids is a lowdensity, highapi gravity liquid hydrocarbon phase that generally occurs in association with natural gas. There are various flow regions encountered in a gascondensate reservoir, along with the pressure profile and the liquid dropout. Composition variation during flow of gascondensate wells. During reservoir depletion liquid condense out of the gas. Simulation of gas condensate reservoir performance keith h. The purpose is usually to predict the behavior of a reservoir to different production scenarios, or to increase the understanding of its geological properties by comparing known behavior to a simulation using different. The generalized form is obtained by manipulation of martins eos 1 and is applied in this study. I nnovative p etrotech s olutions, inc compositional simulation, gas condensate exercise. Fluids and reservoir conditions 28may2014 instituto superior tecnico 9 fluids composition. Pdf gas condensate reservoir engineering researchgate.
The well was producing a gas condensate reservoir and questions were raised about how. Stanley kleinsteiber is a senior petroleum engineer with mha petroleum consultants inc. Agreement between resulting blackoil and fully compositional simulations of gas condensate reservoir depletion is. Flow behavior of gascondensate wells stanford university. The need for integration had been recognized earlier particularly for gas condensate reservoir, gas cycling processes, and volatile oil systems. Jan 30, 2016 chapter 5, part 1 of the online course in applied petroleum reservoir engineering. Fluid flow simulation on a reservoir containing a large. This article describes the steps necessary to conduct a detailed reservoir simulation study also see reservoir modeling for simulation purposes. In fact, in the early days of compositional reservoir simulation, a nondynamic integration of these two was the norm. The depletion of gas condensate reservoirs to pressures below the dew point has been studied by reservoir engineers for many years. Gas reservoirs lend themselves to easy calculation of the hydrocarboninplace through a general gas law equation. Calculate the number of poundmoles in gas by dividing the gas condensate ratio gas volume in cubic feet per barrel of condensate by 379. The simulation occurred with the help of the software below.
Pvt fluid sampling, characterization and gas condensate. The compositional case optionally uses tabular kvalues versus p, rather than equation of state fugacitybased kvalues. Simulation study of enhanced condensate recovery in a gas. Accurate forecasting of gascondensatewell productivity usually requires finegrid numerical simulation to model the formation of the condensate bank and to account for highvelocity phenomena. Condensate dropout of the synthetic gascondensate mixture used for experiments 85% c 1 and 15% nc 4 in mole fraction at 70 o f from the simulation of cce. Simulation study of enhanced condensate recovery in a gas condensate reservoir iranian journal of chemical engineering, vol. Typical molar compositions of petroleum fluids from pedersen et al. In this chapter, gas reservoirs have been divided into three groups. Optimal injection time and parametric study on gas. Reservoir simulation ertekinabbaszadeh ips2014 v2 ma. Retrograde condensate reservoirs produce gas to liquid ratios of about 3150 mcfstb. Its presence as a liquid phase depends on temperature and pressure conditions in the reservoir allowing condensation of liquid from vapor. Condensate dropout of the synthetic gas condensate mixture used for experiments 85% c 1 and 15% nc 4 in mole fraction at 70 o f from the simulation of cce. The term wet gas is sometimes used as more or less equivalent to gas condensate.
Reservoir simulation an overview sciencedirect topics. There are three steps in developing a representative fluid model. Spe 12278, reservoir simulation symposium, san francisco, 1983, jpt, august 1987 pp. During the production of a gascondensate reservoir, heavier hydrocarbon components in the gas drop out as liquid when the reservoir pressure declines below the fluid dew point pressure nagarajan et al.
Understanding the behaviors of gas condensate reservoirs. Natural fractured reservoir engineering phdg textbooks in preparation, intended to be issued during 2015. Calculate the number of poundmoles in gas by dividing the gascondensate ratio gas volume in cubic feet per barrel of condensate by 379. However, calculation of hydrocarboninplace of a gas condensate reservoir is more complex because of the change from a single gaseous phase in the reservoir to two phases gas and condensate at the surface. Spatial distribution of oil, water and gas saturations build and run a reservoir simulation model.
Lean gas condensateleanlean gas condensate gas condensate rich gas condensaterichrich gas condensate gas condensate 0 0. Pressure decline below the dew point pressure causes condensation to occur which creates a hydrocarbon liquid saturation in the reservoir. Accurate prediction of well reauirements in gas the relative significance of positive coupling and inertial effects on gas condensate relative yroauctlvlty ana condensation ecovery mea spe 30767, uctlon ijue to 8. Four reasons why your gas condensate fluid model is probably wrong by tom fontaine, fekete australia pty ltd the generation of a representative fluid model is critical for realistic simulation of gas condensate reservoirs. Pdf on sep 10, 2015, ali vatani and others published gas condensate reservoir engineering find, read and cite all the research you need. Simulation study of enhanced condensate recovery in a gascondensate reservoir iranian journal of chemical engineering, vol. Oil and gas reservoirs structure is a set of geological horizons representing bedding planes two related issues are involved in choosing a grid for reservoir simulation. Chapter 5, part 1 of the online course in applied petroleum reservoir engineering. Modelling and simulation of a gas condensate reservoir. Only the co 2 molar fractions from the gas and oil are known oil. Gas reservoir management training course petroskills grm. Compositional modeling of gas condensate reservoirs.
Ferro implementation of inflow control devices in gas condensate reservoirs using reservoir simulation master. Estimation methods for heterogeneous oil and gas reserves include analogy, volumetric, decline analysis, material balance calculations, and reservoir simulation. Presently, gascondensate reservoirs experience reductions in productivity by as much as a factor of 10 due to the dropout of liquid close to the wellbore. A condensate gas scenario is considered to illustrate the influence of pvt data on the performancebased reserves estimation.
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