Microseismic Logging of the Ekofisk Reservoir

摘要: Microseismic events or acoustic emissions induced by petroleum extraction in the Ekofisk field operated Phillips Petroleum Licence 018 group Norwegian sector of North Sea, were monitored for 18 days April 1997. The monitoring consisted a 6 level, triaxial VSP Wireline tool deployed within reservoir 2/4-C11a observation well located near crest field. 2100 microseismic recorded, corresponding to roughly 5 per hour. majority upper part reservoir, predominantly low porosity layers overlying relatively porous which are undergoing water flooding and compaction. Events most accurately borehole, with position further away being more uncertain. A cluster activity surrounded nearby C16, confirming event positioning accuracy.Within 300 m well, precisely an accuracy better than 30 m, found along discrete lineations. These lineations, parallel major structures region, attributed deformation pre-existing fractures. Comparisons simulations flood front indicated that saturated zones around injection wells aseismic. was not enough known test if any clusters microseismicity associated it. However, compaction chalk may be strongest at front. If significant proportion total is caused association front, then time-lapse could represent useful tracking flood.