Petroleum Experts REVEAL PLATFORM FOR SPECIALISED RESERVOIR STUDIES

Transcription

1 Petroleum Experts REVEAL PLATFORM FOR SPECIALISED RESERVOIR STUDIES

2 Copyright Notice The copyright in this manual are the property of Petroleum Experts Ltd. Petroleum Experts Ltd. All rights reserved. IPM suite, GAP, PROSPER, MBAL, PVTP, REVEAL, RESOLVE, IFM, IVM, IVM Well Test ModelCatalogue and OpenServer are trademarks of Petroleum Experts Ltd. Microsoft (Windows), Windows (Vista) and Windows (7) are registered trademarks of the Microsoft Corporation. Eclipse and Petrel are registered trademarks of the Schlumberger Corporation VIP is a registered trademark of the Landmark Corporation

3 Platform for Specialised Reservoir Studies THE REVEAL CONCEPT REVEAL, like the whole IPM suite, has been created to integrate those disciplines usually isolated by separate tools, in order to better understand the field. REVEAL allows integration at the reservoir level. Most oil and gas companies carry out two types of reservoir study: Full field numerical simulation studies, using tools such as Eclipse, VIP, etc. Specialist studies such as - Thermal and mobility studies to assess well injectivity and productivity - Production chemistry studies - scaling and souring - Sanding and solids deposition and transport - wax and asphaltenes - Thermal and hydraulic fracturing - Enhanced oil recovery methods - steam and gel injection These two types of study are often carried out in isolation. REVEAL, however, enables users to bridge the gap between numerical simulation studies and specialist reservoir studies. REVEAL is a component part of the Integrated Production Modelling (IPM) suite of technical software created by Petroleum Experts. REVEAL Platform for specialised reservoir studies SSSSSSSSS SSSSSSSSSSS SSSSSSSSSSS SSSSSSSSS SSSSSSS Numerical Simulation Geology Surface Network Connectivity Hydraulic and Thermal Fracturing History Matching Geophysics Water Chemistry Studies Souring Studies Heavy Oil Recovery Eclipse VIP Petrel SSSSSSSSS SSSSSSSSS SSSSSSSSSS SSSSS SSSSSSSSSSS SSSSSSS Common Modelling Platform REVEAL REVEAL BRIdGES THE GaP BETWEEN RESERVOIR SIMulaTION STudIES and SPECIalIST RESERVOIR STudIES It Integrates Workflows from diverse Reservoir disciplines 3

4 REVEAL REVEAL ITS ROLE AND PURPOSE REVEAL allows reservoir engineers, production technologists and reservoir specialists to integrate all their studies. The advantages of this are manifold:- A global understanding of field behaviour from a combination of dynamic, thermal and geomechanical data. The ability to use the corporate numerical simulation model to understand how results of previously isolated specialist studies will impact across the whole reservoir. Management of the reservoir on a daily and long term basis in response to its actual physical behaviour. The capacity to share information across disciplines throughout the organisation. REVEAL can be linked to surface network models (i.e. GAP) using the IPM controller software RESOLVE. As a result one can perform system-wide optimisations which may integrate additional reservoir models (whether modelled in MBAL, REVEAL or another reservoir simulator), as well as process and/or economic calculations. Steam injection in horizontal wellbore A REVEAL CASE EXAMPLE What will be the impact of injecting water at sea temperature into a 90 to 100 ºC reservoir? In the example case, an injectivity test has shown good injectivity potential. However, with the injection system tied in the ability to inject water has deteriorated. It could be assumed that the well is being plugged. In reality the injected water has cooled down the reservoir, increasing the water viscosity and thus decreasing the water's mobility. (At a pressure of 5000 psig, for example, the viscosity of a 75,000 ppm water will increase by a factor of four when passing from 100 ºC to 20 ºC.) The amount of water injected for a specific wellhead pressure will be less than predicted if the model is isothermal (assumed to be at constant temperature), affecting the pressure maintenance of the field and therefore its recovery. By utilising the corporate numerical simulation model in REVEAL it is possible to accurately evaluate the impact on pressure and regulate water injection in the field accordingly. 4

5 Platform for Specialised Reservoir Studies REVEAL: TECHNICAL CAPABILITIES As well as the standard reservoir simulator models, REVEAL has the following advanced technical models:- Model Thermal Fracturing Hydraulic Fracturing Water Chemistry Souring Chemical adsorption Polymer and Gel Surfactant Filter Cake Solid Transport Well-Bore Heating Steam asphaltene and Wax Wellbore Flow Attributes Integrates thermo and poro-elastic effects on reservoir stress with injection profile and fracture mechanics Production fractures Chemical equilibrium of mixed waters, predicting precipitation, dissolution and scale inhibition Growth and respiration effect of sulphate reducing bacteria causing H 2 S formation in the reservoir, based on carbon source and bacteria activity Retardation and permeability reduction effects Mobility changes for aqueous phase, including shear thinning, gelation reactions and cation exchange 4th phase micro-emulsion model using ternary diagrams Filter cake formation linked to solid injections in wells and fractures Sand transport, trapping and generation: permeability reduction due to particle trapping Microwave and electrical heating of heavy viscous oils Steam injection model for huff & puff, SAGD Flocculation and trapping model leading to permeability reduction Heat and mass transport inside multiple tubings in a single well, including ICDs, Gravel pack and Counter flow CONNECTION TO OTHER SOFTWARE Software Eclipse Import VIP Import Petrel Import IPM Integration OpenServer Attributes Automatic import facility allowing use of existing Eclipse decks within REVEAL Imported models have been tested and demonstrated to give identical results Automatic import facility allowing use of existing VIP decks within REVEAL Automatic import/export facility enabling use of Petrel formats within REVEAL PROSPER lift curves, Petroleum Experts PVT matching and GAP optimisation using RESOLVE Built-in, full OpenServer functionality, for automatic or batch processing of runs and/or connection to third party software USER INTERFACE Wizard data input 2d and 3d graphics Simplified data entry, verification and visualisation prior to calculation Can be viewed during simulations OPERATINg SySTEM REVEAL runs on a PC running Windows XP or Vista - 32 Bit. A 64 Bit version will be released in

6 REVEAL REVEAL SPECIALISED RESERVOIR ENgINEERINg MODELS: FURTHER DETAILS Thermal and Hydraulic Fracturing A numerical finite-element model for fracture initiation and propagation is directly coupled to the finite-difference 3D simulator. Whereas thermal fracturing increases injectivity, lower injection temperatures may decrease it, as a result of the reduced mobility of the reservoir oil and water. This may also cause flooding problems. The model is based on the pressure balance within the fracture and the reservoir stress field, including poro-elastic and thermo-elastic stress reduction effects. The elasticity of the rock determines the internal shape of the fracture. The shape of the fracture near its tip affects its ability to overcome the critical stress intensity (i.e. strength) of the rock and propagate. Flow within the fracture and leak-off levels are also calculated, providing a fully consistent dynamic model. Thermal fracture calculation within refined region (pressure on full reservoir and temperature) Steam Injection A fully implicit steam injection model can be used to model steam injection strategies such as 'huff & puff' (cyclic steam injection), and SAGD. Thermal profile between and injector and produced of a steam injection system. Solids REVEAL can define solubility characteristics and plugging effects within a reservoir, enabling the user to model wax and asphaltene precipitation and any consequent reduction in permeability. A compression filters cake model (showing the reduction in filter cake porosity and permeability as the pressure drop across it increases) models injection damage resulting from particulates within an injector. This can be used to assess both unfractured and thermally fractured wells. A solid transport, trapping and permeability reduction model is also available within REVEAL, of value to both producers and injectors. 6

7 Platform for Specialised Reservoir Studies MOBILITy CONTROL Thermal viscosity effects impact both on water injectivity and the consequent relative mobility of cooled water and oil. Gel, polymer, chelating agent, cross-linker and foam mobility control of the aqueous phase can all be modelled to enable users to minimise flooding and reduce water breakthrough. Non-Newtonian oils can also be modelled for situations where the apparent viscosity reduces with applied shear stress. Phase desaturation, resulting from changes in interfacial tension, can be modelled as a function of capillary number, either when surfactants or a wetting agent is added, or when the fluid interfacial tension is affected by temperature, pressure or Rs. Injection cycle strategies can be appraised by modelling relative permeability hysteresis. Dispersion and diffusion models are available to track trace components. A well-bore heating model is also available to model increases in productivity near a well heated electrically or by microwave. Water Viscosity (cp) for thermal water injection Phase Emulsification If a surfactant is injected, the interfacial tension between the water and oleic phases will reduce and an intermediate (u-emulsion) may be generated. This may favourably increase the mobility of heavy oils. The effect can be modelled in REVEAL by calculating an effective salinity from concentrations of surfactant, polymer, and alcohols, and the temperature and equivalent alkane number (EACN). A ternary diagram can then be used to calculate the phase saturations. 7

8 REVEAL WaTER CHEMISTRy Mixing of incompatible waters due to a particular injection strategy can result in scale or souring. REVEAL has a comprehensive water chemistry capability, and a large database of reaction species and pathways. Models can be used to predict solid precipitation and dissolution as the chemical species are transported through the reservoir. Scale inhibitor and reversible/irreversible adsorption models in REVEAL can model the behaviour of the precipitates. Souring catalysed by bacterial action, and partitioning of H 2 S between the aqueous and oleic phases, can also be modelled. Multiple thermal fracturing Polymer injection in horizontal wellbores Water streamlines in a waterflood scheme study 8

9 Platform for Specialised Reservoir Studies WELL MODELLINg Development of Deep-Water and EOR projects lead to the usage of complex well geometries To optimise the design of these wells, it is required to understand the effects of the following elements: - Multilateral - Flow within the laterals Understanding of the X-Flow Multilaterals model inclined reservoir with multiple contacts - Smart Wells - Downhole control valves Understanding of the effects of the valves optimising their size and location - Heat exchange between the reservoir and the different components of the well (i.e. casing flow, tubing flow...) Behaviour of steam circulation wells and associated heat exchange steam quality - Counterflow - Fluid circulation, ICV modelling... - Transient behaviour - Gravel Pack Modelling - ICd and ICV control - Bare pipe, annular flow, dual tubing and Coiled tubing Well Modelling This type of modelling compliments and extends what can be achieved with analytical models. 9

10 REVEAL ROCk MECHANICS & FRACTURE MODELLINg Production Optimisation is major topic in current oilfield developments. Part of this optimisation can be achieved by better understanding: - Injectivity behaviour - Reservoir integrity - When will the reservoir fracture, when will we produce sand? Rock Mechanics and Fracture Modelling are required to gain an understanding of these phenomena s. Adding these studies to a standard reservoir modelling approach will be essential in projects such as: - EOR processes such as polymer, which rely heavily on injectivity. Will require a good description of the reservoir rock mechanics. Assist to answer: - What is the maximum pressure at which we can inject without fracturing? - If fractures are created, how will this affect the polymer flood pattern? - CO2 injection processes Potential dissolution of the matrix weakens the rock. Will the CO2 injection lead to rock failure, compaction? - Water flooding processes Formation of fracture will modify the water injectivity and waterflood. Temperature variations will affect the water mobility but also the stress field around the injector. Explicit of Overburden - Without an explicit or analytical model for overburden, compaction on the reservoir surface is over-estimated 10

11 Platform for Specialised Reservoir Studies EOR PROjECTS The high oil price and technology improvements have lead to a large number of EOR projects / EOR studies being carried out Essential technical aspects to understand and optimise the behaviour of these systems: - Detailed PVT description Complex HC fluids such as retrograde condensates Non-HC fluids such as CO2, N2 - Reservoir fluid and fluid / formation chemistry Reactions between the formation and injected fluids Adsorption of solids on to the formation and associated permeability reduction Reactions between different injected fluids - Shear dependant fluid rheology models Non-Newtonian HC and injected fluids - Thermal models - Detailed well descriptions Modelling these elements require integration between specialist studies and global reservoir studies Full field numerical models combining chemical, thermal, rock mechanics and flow capabilities are required to gain an understanding of these projects. CO2 injection: Gas reservoir depletion followed by CO2 injection - Compositional Modelling of fluids - Water Chemistry Illustrates the matrix dissolution - Rock Mechanics Study the risk of rock failure - Understand the reservoir integrity for present and future conditions - Diffusion Modelling - Coupling to RESOLVE, GAP and PROSPER to model the important thermal dependence of CO2 (dense phase injection) Chemical Flooding - EOR - Polymer - Improves the oil sweep efficiency by reducing the ratio between water and oil viscosities Polymer Injection Model - Alkali - Create a surfactant soap within the reservoir from reaction with acidic oil Modelling the alkali - Surfactant - Mobilise residual oil by reducing interfacial tension 11

12 REVEAL WaTER FlOOd MaNaGEMENT We can optimise producers to maximise productivity using RESOLVE/GAP Can we optimise where we inject the water to help maximise productivity and recovery? REVEAL may use streamline calculated drainage regions to identify and weight injectors according to the marginal support they provide for producers Water cut break through times predicted and may be used to control production to delay water production Case 1:No water flood management or optimisation Case 2: With water flood management, no optimisation Case 3: Production optimisation without water flood management Case 4: Optimisation of production and water flood simultaneously Water Flood Optimisation while also optimising production with IPM RESOLVE Model Reservoir Water Flood Model 12

13 Platform for Specialised Reservoir Studies What will be the impact of the thermal injection of non-reservoir water? Is it possible to estimate the impact of thermal and chemical effects on the reservoir? Fully thermal simulation (Viscosity impact on fluid mobility, steam, wellbore heating) Coupled rock mechanics (Thermal and hydraulic fracturing) Polymer, gel, Surfactant, Foamer mobility control Sand production, transport and plugging Scale and souring chemistry models Eclipse and Vip Model Import Specialised Reservoir Studies Platform Thermal Injection & Fracturing Scaling: Reservoir & Tubing Surface Network Connectivity Heavy Oils Recovery Souring Complex Wellbore Flow 13

14 REVEAL How does the temperature of injected water affect injectivity? What is the potential for fracture initiation/propogation? Fracture geometry description Effects of mobility changes Fully thermal reservoir modelling Fracture initiation and propagation model Effect of reservoir temperature evolution Specialised Reservoir Studies Platform Thermal Injection & Fracturing Scaling: Reservoir & Tubing Surface Network Connectivity Heavy Oils Recovery Souring Complex Wellbore Flow 14

15 Platform for Specialised Reservoir Studies Is the injected water compatible with the reservoir's water? Where will scale form? Will it be transported to the producers? Will it be adsorbed on the rock surface? Will it affect permeability? Adsorption Isotherms Scale inhibitor modelling Full thermal chemical equilibrium calculated Water / Oil / gas partitioning for H2S, CO2 and N2 Pre and post simulation chemical calculators for results analysis Specialised Reservoir Studies Platform Thermal Injection & Fracturing Scaling: Reservoir & Tubing Surface Network Connectivity Heavy Oils Recovery Souring Complex Wellbore Flow 15

16 REVEAL How will the surface network response affect productivity? Can a field model encompass both reservoir and economic factors? Multiple simulations dynamically connected to surface network solver and optimiser Advanced IPR calculation and well control methods aid stable connection Dynamic link to reservoir, process and economics models Event driven scheduling options global non-linear optimisation Scenario manager and computer clustering capabilities out of the box Specialised Reservoir Studies Platform Thermal Injection & Fracturing Scaling: Reservoir & Tubing Surface Network Connectivity Heavy Oils Recovery Souring Complex Wellbore Flow 16

17 Platform for Specialised Reservoir Studies What is the most economical method to recover heavy oils? What thermal processes should be used? Can oil recovery be increased? Four phase surfactant model Polymer, gelation Reaction Viscosity Models Steam Model: Huff and Puff and SAgD capabilities Full thermal coupling of wellbore and reservoir heat transport Advanced thermal PVT correlations and matching developed for heavy oils Specialised Reservoir Studies Platform Thermal Injection & Fracturing Scaling: Reservoir & Tubing Surface Network Connectivity Heavy Oils Recovery Souring Complex Wellbore Flow 17

18 REVEAL Will there be a problem with souring? How can it be quantified? Where is it likely that H2S will be created? When will it reach the producers? Specialised Reservoir Studies Platform Thermal Injection & Fracturing Scaling: Reservoir & Tubing Surface Network Connectivity Heavy Oils Recovery Souring Complex Wellbore Flow 18

19 Platform for Specialised Reservoir Studies For more complex well completions, how can we model the heat and mass transfer inside multiple tubings? Specialised Reservoir Studies Platform Thermal Injection & Fracturing Scaling: Reservoir & Tubing Surface Network Connectivity Heavy Oils Recovery Souring Complex Wellbore Flow 19

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