We describe here a test of a new technology for successfulrndrilling of horizontal wells in thin oil columns. Wernconstructed a three-dimensional (3D) earth model of thernoverburden and of the target reservoir layers on the basis ofrnpredrilling data and updated this model in real time on thernbasis of logging-while-drilling (LWD) measurementsrntransferred to remote locations using the World Wide Web.rnThis strategy allowed us to check and update the plannedrndrilling trajectory continuously with all the informationrnavailable at any given time.rnWe used uncertainties in the depth of markers observed inrna number of offset vertical wells to determine the uncertaintyrnin the thickness of layers in the earth model. This 3D modelrncomprised best estimates of the thicknesses and a covariancernmatrix that quantified their initial uncertainties. We thenrndrilled a pilot well. Trajectory data, LWD logs, and resistivityrnimages from downhole measurement-while-drilling (MWD)rnand LWD tools were transmitted in real time from thernSimpson No. 22 drill site in Indiana to a prototype applicationrnrunning in Connecticut. As we acquired new measurements inrnthe pilot well, we compared log curves predicted by the modelrnto the measured logs. Our prototype allowed an interpreter tornupdate the location of markers as the well was drilled; anrnupdate of the entire 3D earth model and its uncertainty wasrnthen automatically computed in near-real time. Quantifiedrnuncertainties are key in this stage to ensure that the modelrnupdate is in agreement with all the data considered previously.rnThis procedure was repeated while drilling the horizontalrndrain hole, which was successfully steered within a dipping 6-rnft-thick layer for 808 ft.rnOur prototype also allowed for remote collaboration: 3Drnmodel updates, LWD data, and resistivity images werernavailable to collaborators who were connected to the networkrnand simultaneously ran copies of the prototype at additionalrnlocations. In particular, the remote availability of real-timernresistivity images was key to the successful well placement, asrnthese images show how the well trajectory follows thernlayering. Remote collaboration means that drilling decisionsrncan be made collaboratively by a globally distributed team in arnsecure network environment. This can be a key capability forrngeosteering, especially in remote locations or when staffingrnis constrained.
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