Predicting Water Cut - A Geological Profile

Abstract

The Wytch Farm Oilfield produces -95rnstbld oil from a Triassic fluvial sandstone reservoir. Water cut has increased over recent years at a rate of 1 500b/dlmonth.P1ot of water cut against time for individual welis reveal two characteristic profile types, either smooth or erratic. Analysis of production data, production logging data and core data indicates that water cut behaviour is controlled by heterogeneity of the sand over the interval perforated.\Vhere production logging data indicate fluid production from a single, thick homogeneous sand, water cut develops with a smooth, progressive proflle. Core data show that these sands have a uniform vertical permeability and water cut develops with a progressive, gravity stable, flood front.In weils where most of the flow is from a small number of thin sands, water cut develops in a step change marmer. Core reveals that these thin, highly productive sands have permeabilities > l000mD and are sandwiched between thick sequences dominated by low permeability (<5OrnD), nonproductive sands. The "steps" are caused as successive high permeability sands switch abruptly from oil to water.The relationships described above occur as end members of a continuum, Welis develop a unique water cut profile depending on the nature and distribution of sands perforated. Using this geological model, remedial well operations have been successfully optimised to maximise fleld productivity.

Neurons differentially control expression of a herpes simplex virus type 1 immediate-early promoter in transgenic mice

“…It is unlikely that sequences within the ␤-galactosidase coding sequence play a role in determining the expression pattern, since this gene has been used previously as a reporter in similar studies (3-5, 12, 19, 27). Even though a basal level of ␤-galactosidase activity was detected in transiently transfected mouse L cells and in transgenic peritoneal macrophages in culture (28), no ␤-galactosidase activity was seen in any of the tissues listed as negative. These tissues included liver and lung, which contain many macrophages.…”

“…No detectable increase in activity of the ICP4 promoter has been observed under conditions that should result in reactivation of HSV-1. Neurons of the trigeminal ganglia did not demonstrate activation of the transgenic ICP4 promoter after explant cocultivation for 1, 2, 3, or 4 days postexplant (28). There are a number of possible explanations.…”