Maximising the Use of Horizontal Well Data in the Structural Framework ofthe Reservoir Modelling Workflow: A Case Study of a Middle East CarbonateReservoir

摘要

This paper summarizes an efficient workflow for building a reliable static model reference case byimproving the accuracy of well placement in a hydrocarbon bearing structure.This is beneficial inoptimising upcoming well target position and trajectory planning as well as during the dynamic historymatching process.In a non-operated venture,the ability to generate an up-to-date static model that maintainspace with operations,provides valuable insight to advise the operator on the upcoming drilling plan andcontinuously supports the dynamic model for reserves booking,is highly sought after.The systematic approach described in this paper is applied to a geo-model from a Middle East carbonatereservoir consisting of over 50 wells with good quality PSDM seismic data.The workflow presentedbegins with seismic mapping,utilizing volume-based modelling techniques,followed by structural elementcorrection using borehole images (e.g.structural formation dip and true stratigraphic thickness estimate)and finally introduces alternative control points,which enable drilled wellbore trajectories to be structurallyanchored,based on layer thicknesses and structural trends within the target reservoir.Using this approach it is possible to generate a consistent structural model that honours geologicalmarkers,measured dip ranges and structural trends seen from seismic data and image logs.During theprocess one learns more about data quality (e.g.scale of data resolution and depth of investigation),associated with specific fields and carbonate reservoirs through the interaction between geological,geophysical and petrophysical disciplines and ensures their correct use.Data are used to improve theraw interpreted seismic horizons by calibrating mapped thickness distribution against the well tops.2Dvisualizations are generated on a well-by-well basis,including map views,curtain sections (along eachhorizontal well),composite cross-sections and 3D visualizations to show inter-well relationships withindifferent geological layers.As a result the well is placed in the correct structural position.Correct wellplacement,especially of highly deviated/horizontal wells,provides more accurate identification of reservoirsweet spots,leading to improved well target position and trajectory planning for upcoming wells,and arobust baseline to achieve production/well test history match during the dynamic modelling process.