Geomechanical characterization of igneous intrusion for successful well testing

PreviousNext No AccessFirst International Meeting for Applied Geoscience & Energy Expanded AbstractsGeomechanical characterization of igneous intrusion for successful well testingAuthors: Rajeev KumarJoseph ZachariaRajeev KumarSchlumbergerSearch for more papers by this author and Joseph ZachariaSchlumbergerSearch for more papers by this authorhttps://doi.org/10.1190/segam2021-3582023.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail AbstractEmplacement of magma has led to the development of extensive networks of igneous intrusions in the subsurface of many sedimentary basins worldwide. There are several examples of hydrocarbon fields associated with igneous rocks around the world (Schutter, 2003b). The circulation of related hydrothermal fluids, which may reduce the porosity and permeability of host rock reservoirs, and associated host rock deformation often result in the formation of “forced fold” traps. Understanding the geometry and evolution of subvolcanic intrusive networks in volcanogenic basins is thus of interest to the petroleum industry. Present study is about such intrusion and associated successful hydrocarbon production from one well in the western offshore.An integrated analysis has been carried out using Mechanical Earth Model (MEM) built using sonic dipole data, Stoneley based fractures analysis, borehole image, resistivity curves separation, gas peaks and critically stressed fracture (CSF) analysis to estimate feasible depth intervals for perforation in intrusion encountered in one of the well at western offshore. Most of the gas peaks in range of 0.1%-0.5% while drilling have been reported at transition zone of high Young’s Modulus to lower Young’s Modulus with both Up and Down Stoneley fractures showing possible fracture sets. Borehole images have been used to pick dip and azimuth of fractures. Shear and normal stress components acting on fractures has been estimated to predict mechanical behavior whether unstable or stable in present stress state. A pre-existing discontinuity, i.e. fault or fracture, will re-activate when the shear strength on the fault/fracture plane is exceeded i.e. slippage occurs along the discontinuity. The discontinuity is then referred to as unstable. If the shear strength on the discontinuity plane is not exceeded, the discontinuity is referred to as stable under the current stress state.With planned open hole testing, risk analysis of collapse pressure with drawdown has been conducted to prepare suitable fluid (12ppg). Typical breakdown pressure EMW ranges 17ppg-23ppg against target zones with closure pressure in range of 5700psi-7800psi. Considering lower cohesion and fraction angle in fracture, few fractures are identified as critically stressed. With increase in fraction angle up to 20deg, injection of 2800psi-3500psi is required to make fractures conduit.Barefoot testing results with surge pressure upto 4500psi helped to have good production rate. Later, sonic dipole data has been acquired and compared with prior testing results to identify flow zones. Hole shaped changed with possible fracture slippage with drawdown. Successful testing of intrusion has provided confidence to explore more such reservoirs in the field.Keywords: basement, acoustic, geomechanicsPermalink: https://doi.org/10.1190/segam2021-3582023.1FiguresReferencesRelatedDetails First International Meeting for Applied Geoscience & Energy Expanded AbstractsISSN (print):1052-3812 ISSN (online):1949-4645Copyright: 2021 Pages: 3561 publication data© 2021 Published in electronic format with permission by the Society of Exploration GeophysicistsPublisher:Society of Exploration Geophysicists HistoryPublished: 01 Sep 2021 CITATION INFORMATION Rajeev Kumar and Joseph Zacharia, (2021), "Geomechanical characterization of igneous intrusion for successful well testing," SEG Technical Program Expanded Abstracts : 181-185. https://doi.org/10.1190/segam2021-3582023.1 Plain-Language Summary KeywordsbasementacousticgeomechanicsPDF DownloadLoading ...