Seal Integrity of Late Jurassic to Early Cretaceous Mudrocks of the South-Western Barents Sea Area
O.Y. Ogebule, N.H. Mondol and J. Jahren
Event name: 77th EAGE Conference and Exhibition 2015
Session: Shale Geology
Publication date: 01 June 2015
Info: Extended abstract, PDF ( 1.35Mb )
Price: € 20
Top seals are as important as reservoirs and source rocks for hydrocarbon exploration success. Upliftment is agreed to have a great influence on the petroleum system in the Barents Sea area. Seal integrity assessment is thus embarked upon to enhance the knowledge needed for future exploration and exploration targets. For the purpose of this study, two wells labelled Well A and Well B are investigated in the south-western Barents Sea Area. Well cuttings from possible sealing mudrocks to known reservoirs are provided for grain size analyses. A Suite of well logs including gamma ray, compressional wave velocity and bulk density are used. Brittleness index (BI) are estimated through different methods to determine the risk of seal failure. These methods include overconsolidation ratio for estimation of degree of upliftment; log-derived unconfined compressive strengths, Young’s modulus versus Poisson’s ratio, Lambda-Rho versus Mu-Rho, mineralogy and grain size. Brittleness index reveals that all the investigated mudrocks are good seals, but in Well A, the Fuglen and lower unit of the Hekkingen Formations may be more brittle than other Formations while in Well B, parts of the Kolmule Formation is of higher risk to fracturing than the other Formations.