Trasys International (Belgium)

Space robotics poses unique challenges arising from the limitation of energy and computational resources, and the complexity of the environment and employed platforms. At the control center, offline motion planning is fundamental in the computation of optimized trajectories accounting for the system’s constraints. Smooth movements, collision and forbidden areas avoidance, target visibility (TV), and energy consumption are all important factors to consider to be able to generate feasible and optimal plans. When mobile manipulators (terrestrial and aerial) are employed, the base and the arm movements are often separately planned, ultimately resulting in suboptimal solutions. We propose an optimal whole body planner based on discrete dynamic programming and optimal interpolation. Kinematic redundancy is exploited for collision and forbidden areas avoidance, and to improve target illumination and visibility from onboard cameras. The planner, implemented in the Robot Operating System (ROS), interfaces the 3D Rover Operations Control Software (3DROCS), a mission planner used in several programs of the European Space Agency (ESA) to support planetary exploration surface missions and part of the ExoMars Rover’s planning software. The proposed approach is exercised on a simplified version of the Analog-1 Interact rover by ESA, a 7-degrees of freedom robotic arm mounted on a four wheels nonholonomic platform.

Summary Some practical methods that can be used to enhance our geological estimate of vertical and horizontal permeability on a simulation-scale are outlined. Core and outcrop information for a turbidite fan reservoir is used to illustrate the importance of estimating vertical permeability. Bed-scale modelling can assist in determining directional permeability for a particular facies association. Identification of cells where baffles may be expected can be incorporated into the workflow to produce a more realistic architecture and improve the inputs for the dynamic simulation.

Abstract This paper describes the proposed re-development of the Galapagos Field, comprising the abandoned NW Hutton field and the Darwin discovery (Block 211/27 UKCS) which forms a southerly extension. The paper covers the initial concept and analytical evaluation, the static uncertainty model build, the dynamic model history-match, the iterations between static and dynamic modelling, the development subsea and well locations, the optimisation workflow of the advanced Flow Control Valve (FCV) completions in both producers and injectors and the facilities constraints. The redevelopment plan involved several multi-disciplinary teams. 20 years of production data from 52 wells were analysed to identify the production behaviour and confirm the significant target that provided the basis for the development concept selection. The full Brent sequence compartmentalised stochastic static model was based on reprocessed seismic plus 14 exploration and appraisal wells. Streamlines, uncertainty sensitivities and mostly good detective work honed a history match to RFT, BHP, PLT and oil and water production. P50, P90/P10 models were selected and over 100 FCVs optimised to deliver the profiles against an identified FSPO facilities’ constraints. Over 1,000 static models were delivered consisting of sheet sands, incised valleys and channels in heterolithic facies overprinted by a depth trend with appropriate uncertainty ranges. The high well count gave a tight STOIIP probabilistic range of 790/883/937 million stb. The early RFTs illustrated extreme differential depletion between Brent zones and subzones of the Ness. To history-match these the dynamic model retained the static model definition in the Upper Ness to capture the thin but extensive shales. The early 18-month depletion and the late steady production-injection phases were simulated separately in prediction mode and matched the Production Analysis estimated ‘future’ production giving confidence to the history matched model. The initial concept development of 4 subsea-centres, to cover the large field area, with an injector in each compartment proved a robust selection. The horizontal wells increase PI where needed and mitigate internal faulting. The optimisation of the FCVs significantly increased oil production from all zones and drastically reduced water injection and production so that the identified FPSO modifications were relatively modest. The final First Stage Field Development Plan consists of 11 producers and 6 injectors across developed and undeveloped areas confirmed robust P50 reserves of 84 million boe. Robust concept selection allowed for early identification of production units so that constraints and modifications could be accounted for within the economic model. The Galapagos field re-development plan is an excellent example of how detailed static and fully history matched dynamic models can lay the foundations for new technology like the optimisation of the FCVs to access bypassed reserves using significantly smaller production units with reduced requirements for power, compression, gas lift, pumping pressure, injection and production. In short, they shrank the facilities.