Tight Reservoir Automatic 3D-Modelling Generator: Turning Complicated into Effortless Application
Authors: Limchuchua Kittipong , Sarisittitham Sawatdiwong , Ruthairung Pichaya , Whangkitjamorn Jugkapun , Sikharin Nuddanet , Jitpipatpong Nitshakhan , Kritsadativud Pannayod 
Published: February 2023

Because tight reservoir has become important energy resources in sustaining production, PTTEP has recently evaluated a number of these reservoirs. For development plan optimization and resources estimation, 3D-modelling is the most efficient tool. However, the complicated workflow usually impedes inexperienced users to work with reservoir simulation. This study aims to construct an automatic 3D-modelling generator which could handle the tight reservoir. This would allow non-simulation expert to construct any 3D models for further simulation study.

In this study, black oil simulation model is selected for simplicity. A generic multi-layer tight reservoir model is consisted of cartesian grids with the local grid refinement (LGR) at a well location to capture flow regime near a hydraulic fracture. The user interface tabs contain input spreadsheet for grid design, rock and fluid properties, initial conditions, well completion, and production schedule. Then, the script files with black oil simulator keywords will be generated. The capability to adjust all the input data is finally introduced to ensure user-friendly interface before finalizing the script files to simulation software without any complication with the simulation keywords.

With the created Tight Reservoir Automatic 3D-Modelling Generator, all complicated workflows (the black oil simulator keywords and structure) are handled. The 3D modelling for tight reservoir does not require highly experienced user anymore. Also, neither high expertise in simulation nor programming is required. The generator provides user friendly interface with full capability of automatic multi-layer model construction. It also can handle any kind of fluid system (oil/gas/water and saturated/undersaturated reservoir), and the presence of a hydraulic fracture in any specific layers. In terms of the well and production control, it provides the option frequently used e.g., control BHP, control THP, control flow rate. This generator has been used in several PTTEP projects which have proven the success of the application. Currently, for the high-level field evaluation of the tight reservoir, any inexperienced user could construct the 3D model for their usage without having to request support from the simulation team. Regarding this advantage, there has been measurable manpower saving for model construction. Therefore, user could have more time to focus on engineering analysis such as sensitivity study on relevant parameters or production forecast and optimization which ultimately bring the best value for the project evaluation.

Although commercial software may be available, they require costs and learning. Also, that software may not fully fit with specific objective. With in-house development of this pre-processer modeling tool, the interface is proven to be ease of use and fit-for-purpose with no additional cost. Further improvement would easily be performed. The concept of coupling the familiar user interface with reservoir simulator could be extended to other opportunity not only in PTTEP, but also anywhere else.