Enhanced Mechanical Earth Modelling and Wellbore Stability CalculationsUsing Advanced Sonic Measurements—A Case Study of the HP/HT Kvitebjorn Field inthe Norwegian North Sea (2007)

Advanced Mechanical Earth Modelling And Wellbore-Stability Calculation Using Advanced Sonic Measurements: A Case Study on an HP/HT Field in the Norwegian North Sea Anke Simone Wendt; Anke Simone Wendt Schlumberger Search for other works by this author on: This Site Google Scholar Marit Kongslien; Marit Kongslien Schlumberger Search for other works by this author on: This Site Google Scholar Lasse Renlie; Lasse Renlie Statoil Search for other works by this author on: This Site Google Scholar Erik Sandtorv Pedersen; Erik Sandtorv Pedersen Statoil Search for other works by this author on: This Site Google Scholar Badarinadh Vissapragada; Badarinadh Vissapragada Schlumberger Search for other works by this author on: This Site Google Scholar Eiliv Skomedal; Eiliv Skomedal Statoil ASA Search for other works by this author on: This Site Google Scholar Bikash K. Sinha Bikash K. Sinha Schlumberger-Doll Research Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Anaheim, California, U.S.A., November 2007. Paper Number: SPE-109662-MS https://doi.org/10.2118/109662-MS Published: November 11 2007 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Wendt, Anke Simone, Kongslien, Marit, Renlie, Lasse, Pedersen, Erik Sandtorv, Vissapragada, Badarinadh, Skomedal, Eiliv, and Bikash K. Sinha. "Advanced Mechanical Earth Modelling And Wellbore-Stability Calculation Using Advanced Sonic Measurements: A Case Study on an HP/HT Field in the Norwegian North Sea." Paper presented at the SPE Annual Technical Conference and Exhibition, Anaheim, California, U.S.A., November 2007. doi: https://doi.org/10.2118/109662-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractGeomechanical interpretations of inhomogeneous anisotropic materials are enhanced by three dimensional (3D) sonic measurements that provide compressional, fast shear, slow shear, and Stoneley wave slownesses in (an)isotropic drilled formations.We investigated the Kvitebjorn high pressure high temperature (HPHT) gas/condensate field for enhanced Mechanical Earth Modelling, and wellbore stability analyses using three-dimensional sonic measurements in overburden and reservoir formations. Kvitebjorn field is situated on the Norwegian continental shelf west of the Viking Graben.In the HPHT Kvitebjorn field, major development challenges are the determination of the drawdown rate and the maximum depletion for optimum production while maintaining rock integrity. These challenges are directly related to the effect of changes in reservoir pressure on the in-situ formation stress state. Using advanced processing of sonic data, we estimated the amount of stress anisotropy, stress orientations, and stress magnitudes at particular reservoir intervals. These stress data together with measured in-situ minimum horizontal stress values were used to calibrate horizontal stress logs perviously estimated in the MEM. Furthermore, we constrained rock elastic properties (deformation, strength) using sonic slownesses and elastic shear moduli calculated from the sonic dataset. These data were later used to estimate rock strength and the onset of wellbore deformation. The two approaches allowed us to calculate (1) isotropic rock properties from the sonic slownesses, and (2) vertical and horizontal rock properties from the calculated shear moduli.Validity of the so-calibrated MEM was subsequently tested estimating wellbore stabilities based on the isotropic rock property data, and the vertical and horizontal rock property data sets. In each case, the model was able to accurately reproduce the events observed during drilling.The work that we present here is intended to open a new direction for geomechanical modelling: To demonstrate a new measurement allowing practical consideration of rocks as an anisotropic material, and to better constrain the effective stress ratio.IntroductionThe Kvitebjorn field is an HPHTgas/condensate field, operated by Statoil ASA in the Norwegian North Sea. Reservoir formations comprise the Brent and Dunlin Groups. They consist of clastic materials, subjected to reservoir pressures of 77MPa and temperatures of 150oC. The field is intensively faulted, with a predominant fault trend in NE-SW direction. High resolution sonic data sets were obtained in several wells, from which one field example is shown here.umerous theoretical and experimental works have been undertaken in the recent past to understand the complexity of high pressure high pressure fields. HPHT means oilfield operations are technically challenging, and have high costs; with the North Sea including some of the most highly overpressured reservoirs in the world. Therefore it is imperative to examine all the available data, and apply all the current knowledge and new technology to assess stresses, and rock properties. Keywords: reservoir geomechanics, depletion, horizontal stress, slowness, equation, Reservoir Characterization, stress magnitude, shear slowness, mechanical earth, wellbore Subjects: Reservoir Characterization, Reservoir geomechanics This content is only available via PDF. 2007. Society of Petroleum Engineers You can access this article if you purchase or spend a download.