In order to improve the recovery from petroleum reservoirs it is important to optimize the directional steering of the drilling. Placement of the well in the reservoir is a very important factor for the recovery of the reservoir. The process of directional steering the drilling according to the geology is called geosteering. Geosteering decisions are generally based on geological models. To make optimal decisions while drilling, it is necessary that geological models for the near wellbore region are well calibrated against measurements and that the uncertainty is quantified. The current work processes for geosteering suffer from shortcomings. (i) It is highly challenging to calibrate geomodels to deep Electromagnetic Measurements (EM) and Logging While Drilling (LWD) measurements for complex formations. (ii) There is a lack of flexibility in the current geomodels for support of structural updates and fast local updates. (iii) There is a lack of a transparent, systematic and consistent workflow for quantifying complex geological uncertainties in the geomodel and considering them when making geosteering decisions.
The primary objective of this project is to develop methodology for geosteering by continuously updating geomodel based on LWD measurements including deep EM measurements. To achieve this objective, we will address the following secondary objectives
- Ensemble-based geosteering workflow. Develop and improve an ensemble-based workflow for geosteering that would integrate seamlessly with reservoir management.
- Processing deep EM measurements. Apply appropriate EM forward modelling tools and investigate efficient processing of EM measurements for integration in geosteeering workflow
- Flexible earth model representation. Further develop a flexible representation of the geological model that supports local updates and uncertainty modelling of the geological structures and properties in real-time.
A first prototype of an interactive Decision Support System has been developed and applied to synthetic cases. The model updating, and the decision recommendations have been illustrated. The results show statistically optimal well landing in complex reservoir navigation cases. The paper "An Interactive Decision Support System (DSS) for Geosteering Operations" was presented at the SPE Norway One Day Seminar April 18th 2018 and was later highlighted in SPE Journal of Petroleum Technology (September 2018: "New Geosteering Work Flow Integrates Real-Time Measurements With Geomodels").