This paper presents an automated method to speed-up the process of history-matching simulation models. A new tool "History Match Process Optimizer– HMPO" was developed to allow local modification of simulation model property arrays around any given well type. Deployment of this tool significantly improved the history-match process of a reservoir simulation model containing a high number of wellbores and a saving of 140 man-hours was achieved.
The tool was developed in LINUX environment and adapted to an in-house developed state-of-the-art reservoir simulator, GigaPOWERS (Dogru et al. 2008, 2009, 2011). The tool has an automated workflow that uses the model perforation file as an input to generate the property modifier file; the perforation file contains all completed wellbores along with their perforated cells. Additional input includes specifying what model property array would be modified around the wellbore (transmissibility, permeability, porosity, fluid contacts, etc.), and number of cells to be modified in 3D directions.
Application of this tool was done on a simulation model as part of the history-match process, 65% of the wells are horizontal or multilaterals. Prior to using this tool, difficulties were experienced when attempting to manually perform local history-match modification around each wellbore to mimic hydraulic fracture completion with fractures extending to several cells away from the wellbore, especially in a fine Giga-scale model with a high number of wellbores. The implementation of HMPO allows a quick generation of the modifier files with ability to repeat the process several times until an appropriate local modifier is achieved for all wellbores at the same time. This made the process of generating the modifier file 200 times faster. Hence this tool became a necessity with large complex models built with high resolution, and advanced computational resources.
The novelty of this work is to assess simulation modeling by providing an automated property-array modification around any given wellbore completion in a way that significantly reduces the duration of history- match process. "HMPO" is an internal effort to speed-up and optimize this part of history match process. Therefore, its application to other big reservoir simulation models in the company would add value, improve efficiency of the process, and enhance the quality of results obtained from history-match calibration.