Extreme GeoSteering in Complex Channel Sand Architecture, a Reality now with High Definition Deep Directional Multi Boundary Detecting Technology: Case Study from Greater Burgan Field, Kuwait

摘要

The Lower Cretaceous Burgan Sands are the primary reservoirs in the Greater Burgan Field in Kuwait.rnBurgan sands are divided into five major units from bottom to top – BGSL2, BGSL1, BGSM, BGSU2 andrnBGSU1. BGSL2 and BGSM consist of stacked, massive fluvial channels. BGSL2, BGSU2 and BGSU1rnmostly consist of delta distributary channels and bays in a tidal delta setting grading to shallow marine.rnThese are discontinuous both laterally and vertically. Channel sand geometry in geosteering perspectivernoften sums up to discontinuous patches of sand lenses at differing stratigraphic levels. Maximizing net payrnin a channel sand reservoir is known to be a very challenging task for the geosteering domain. Navigatingrna drainhole through such geometry requires precision geosteering technologies that can map multiplernreservoir boundaries with high accuracy enabling precise forward designing wellbore trajectory withrnrespect to the dynamic reservoir geometry. Deep directional distance to boundary u0002DTBu0002 technologyrnrevolutionized the whole concept of geosteering in this regard by enabling proactive geosteering for thernfirst time in industry. Introduced in 2005, it features the capability of detecting reservoir boundaries uprnto 15ft around the wellbore and achieved great success all over the world through proactive geosteeringrnin thin reservoir layers and maximizing the percentage reservoir contact. However, this technology isrnlimited to mapping only 2 layers, above and below the tool, up to a distance of 15ft around wellbore. Itrncannot detect a third layer beyond the two layers surrounding it.rnHigh definition deep directional multi boundary detecting technology is a noble advancement on thernfirst generation Distance to Boundary technology. With significantly improved signal to noise ratio,rnsupported by a robust and new multilayer stochastic inversion algorithm that incorporates a whole gamutrnof measurements, principally from 3 firing frequencies (100kHz, 400kHz and 2Mhz), this technologyrnextends its capability by mapping multiple boundaries up to 20ft around the wellbore.rnThis paper examines a case study from the Greater Burgan Field, Kuwait where the extended capabilityrnof this technology has yielded exemplary results in navigating wellbores through very complex channelrnsand geometry with very sharp local dip changes and varying thicknesses. Extreme geosteering is finally made possible with this fit-for-purpose technology in complex subsurface environments, loweringrnconstruction risk while maximizing net pay for each well drilled.