The Hydrocarbon Field Planning Tool (HFPT), recently developed by Shell, provides capabilities for rigorous integrated subsurface-surface production forecasting in the medium to long term (1–30 years). HFPT can be used for gas, gas-condensate, oil and mixed gas-oil fields. HFPT models allow business optimisation by making more efficient use of the existing assets and by reducing investment costs in the new fields. In the simulation, HFPT uses a pressure-balanced solution of the integrated system: from the reservoir(s), through wells and surface facilities, to the delivery point. A wide range of fluid models is available, from simple gas-condensate and black oil PVT models to multi-component models with EOS flash calculations. HFPT provides optimisation functionality for maximising the returns in oil and gas fields, while accommodating operational preferences for production allocation and network constraints. It can also model injection networks and optimal lift gas distribution. Introduction The need for an integrated approach to dynamic field modelling has now been accepted by many players in the oil industry [1]. Issues which can be analysed in an integrated model, and which cannot be adequately addressed in a stand-alone reservoir model (or multiple stand-alone models), include:Pressure interaction between surface and subsurface.Pressure interference between different reservoirs and wells connected to a shared surface facility. An example is a high-pressure well backing out a low-pressure well.Mixing of dissimilar fluids from different reservoirs in the production network.Influence of facility constraints, e.g. separator limits, on a set of reservoirs connected to a shared facility.Production optimisation in the overall system against a set of common criteria. A number of field studies, performed using integrated subsurface-surface models, have already been reported, e.g. [2][3], showing benefits of such models. Over the past ten years, a wide range of applications from commercial vendors have appeared on the market which allow modelling of the subsurface and surface in an integrated way. Most of the available tools are designed either for a very simple reservoir description or for a simple surface description, or both. Hydrocarbon Planning Tool (HFPT) has been developed by Shell to fulfil the need for rigorous integrated subsurface-surface production modelling. It has been designed for accurate medium to long term forecasting, for optimising of production from existing fields, for analysing near-field potential in mature fields and for developing new fields. Currently, HFPT focuses mainly on medium to long term forecasting which is dominated by subsurface behaviour. However, surface and process facilities models can also be modelled in great detail, when needed. Requirements for Integrated modeling An integrated subsurface-surface model consists of the following main data modules, illustrated in Figure 1:PVT model.Subsurface model.Surface production system model.Processing facilities model.Overall integration and control, contracts, optimisation targets, development planning.

Salym Petroleum Development (SPD) has embarked on an ambitious Oil Field Management Improvement Program with as key objectives to:• Optimise Production (2.5% additional production through reduction of Locked-in-Potential and better reservoir pressure maintenance; unscheduled deferment less than 1% through reduction of ESP trips).• Increase Ultimate Recovery (Increase RF by 1%; platform for future EOR project; robust basis for infill drilling).• Reduce OPEX (increase ESP mean time between failure; contain chemical consumption costs; in field staff journies reduced by 10% /annum; less than 3 non-critical loss of integrity incidents per year).