Decisions in today's field development environment and economic conditions must be made in ever-shorter time. The DecisionSpace Nexus solution from Halliburton's Landmark Digital & Consulting Solutions Division provides integrated reservoir modelling and simulation workflows to help asset team engineers make quick and accurate production and reserve forecasts and improve the planning of field development with its necessary facilities. It will also optimise the value of assets faster than any other commercial simulation solution available today.
Only released in October last year Nexus provides unprecedented simulation speed by leveraging a robust volume-balance formulation that results in convergence with fewer iterations or repeats. This improved performance takes place straight 'out of the box' with a minimal tuning requirement to set it up.
Using a fully-coupled and implicit formulation Nexus' simultaneous surface and subsurface simulation process results in more accurate production forecasts, says the leading supplier of software and services for the upstream oil and gas industry worldwide. The direct-access modelling environment it relies on improves user productivity by eliminating the need for data transfers and reformatting. So data preparation and analysis is always fast and easy using the intuitive Windows-based DataStudio pre- and post-processing modules.
Therefore in summary the benefits to your business are:
- Rapid simulation.
- Accurate production forecasts.
- Improved productivity.
The detailed features of the new DecisionSpace Nexus software are:
- Use of a robust volume balance formulation which runs efficiently immediately, with little or no tuning required. The simulator conserves the component mass and achieves convergence in fewer repeated iterations, which results in unprecedented speedy simulation.
- Generalised compositional formulation.
Nexus is a single simulator employing a generalised compositional approach. With the exception of PVT calculations the simulator executes the same code whether the material being studied is black crude or compositional.
So the only input changes needed are for actual fluid data. Nexus simulates multiple reservoirs through a coupling process, which allows different material physics and formulations to be joined up seamlessly. So multiple reservoirs tied to a common surface network are rapidly solved as a single simulation exercise.
The incorporated Network Planner module enables fast and automated generation of surface plans, including features such as flow lines, valves, chokes, manifolds, gas plants and separators. Nexus automatically simulates the entire network with the subsurface, resulting in a better understanding of how the reservoir(s) will behave once development has taken place.
This Network Planner allows the user to design, view and edit both wells and surface facilities in either 2D or 3D viewing windows. It solves the surface network at the Newtonian level together with the subsurface equations, which leads to a fully coupled solution. In each iteration the surface nodes are subsurface grid cells that are solved simultaneously. This results in a completely accurate representation of the total surface/subsurface asset.
A powerful and unstructured linear solver is employed. So a dramatic reduction in CPU cycles can be realised in simulations having large numbers of unstructured non-local connections. These are often present in simulations because of faults, local grid refinements, necessary grid coarsening and 'pitchouts'.
Nexus' integrated workflow flexibility in gridding, up- and down-scaling workflows create a simulator-ready model while at the same time honouring known geological features where necessary. Gridding, up- and down-scaling workflows by means of the add-on DecisionSpace PowerGrid module results in a reservoir-friendly model that fully reflects the subsurface rock conditions. And an intelligent vertical simulation process known to engineers as 'layer lumping' allows users to combine the geological layers.
Automatic local-grid refinement around such physical features as wellbores, faults and channels enables more accurate prediction of resulting fluid flows.
The direct access-modelling environment created by Nexus enables integrated workflows and eliminates the need to import, export and reformat multiple data types. So, as Landmark puts it, "What you see is what you simulate."
Nexus takes full advantage of the latest highperformance parallel computing systems such as use of clusters and grids by switching seamlessly from serial to parallel mode as often as required. The speeding-up recognised in serial mode is amplified when the software is run in parallel. The following hardware is required to run this next-generation reservoir simulator:
- Processor: Opteron, Itanium2 or EM64T 2GB RAM or greater
- Hard disk: 600mb for installation and 200mb to operate
- Graphics adapter: Nvidia Quadra FX500, 1000,1100,1300, 3400, Go700 or 1000, Nvidia Quadro4 380XGL, 900XGL, NVS400.
Additional software as follows is also needed on board:
- Oracle8I Enterprise Client 8.1.7
- Compatibility with OpenWorks R2003
- Hummingbird Exceed 10.0
- Complementary DecisionSpace infrastructure under the Landmark brand.
- Either a Windows 2000, Windows XP or Red Hat Linux Enterprise operating system is required, along with one of the following interconnects for parallel computation: Infiniband (SilverStorm), Myrinet or Gigabit Ethernet.
To sum up, today's energy industries in North Africa and the Gulf are changing fast as new challenges emerge along with market developments. A common feature reported from right across Oil Review's readership area is the constant need to accelerate E&D operations in order to cut cycle times.
So industry professionals are always looking for streamlined processes and cost reduction possibilities. The new reservoirs they need to stay in business get ever more difficult to locate and complex in structure. And they need all the help they can get to improve their understanding of the many uncertainties involved that will actually impact on the economics of any new project.
This all means more cross-discipline integration and accuracy of assumptions made so that better decisions can be taken and risks can be managed, not guessed. Thus workflows need to be executed many times within practical timeframes.
The solution to these challenges facing regional operators today is already emerging in next-generation technologies such as the new DecisionSpace Nexus software for reservoir simulation described here.
© Oil Review Middle East 2006
