| Title | Well Logging Analysis and Wellbore Simulation of Well SV-26 in Svartsengi Iceland |
|---|---|
| Authors | Arief Imam SANTOSO, GrÃmur BJÖRNSSON, Gunnar THORGILSSON, LúdvÃk S. GEORGSSON |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Well logging analysis, injectivity and productivity index, wellbore simulation, wellhead output curve, Svartsengi Iceland |
| Abstract | Reservoir engineering datasets is important in order to have a successfull exploration program. Some of these datasets are obtained from well testing during drilling and recovery. This paper will focus on the analysis of such testing and will take an example of well SV-26 in Svartsengi, Iceland. Analysis of downhole pressure and temperature data in a 2500 m deep, results in a static water table at 425 m, a boiling point with depth zone to 700 m, and near isothermal 240°C single-phase water reservoir to total depth. Two major feedzones are identified at 1225 and 2200 m TVD (total vertical depth) and the well pressure pivot point is located at 1350 m TVD and at 77 bar-g. Multistage injection and production test analysis result in a cold well injectivity index of 11 kg/s/bar and a hot well productivity index of 28 kg/s/bar. Both indicate a very good reservoir. Detailed hydrological models of injection and production transient pressure data show well skin in the negative territory and reservoir permeabilities in the 10-1000 mD range. Higher permeability values arise from models calibrated against well data collected before running the 7†slotted liner. This may suggest that the lower cold water injectivity index relates to liner holes viscosity effects. A numerical flowing wellbore model was able to capture these properties; the bottomhole and wellhead pressure with flow and the dynamic temperature and pressure profiles with depth. The model predicts a shallow to deep feedzone ratio at 2:1. The modelled wellhead output curve infers a much higher maximum flowrate than the tested maximum of 47 kg/s, thereby taking well capacity close to 10 MWe. |