Water production logging in horizontal wells

New technology has enabled operators to drill an increasing number of exten ded reach, lateral, and horizontal wells. In these highly deviated or horiz ontal wells, conventional production logging sensors can be ambiguous in re solving multiphase flows. The successful diagnosis and treatment of water o r gas production problems requires the identification of these specific inf lux zones. Providing reliable production logging solutions in this difficul t environment has led to the development of new sensors which can measure b oth the holdup and velocity of each fluid phase. A novel tool string combin ation has evolved which incorporates sensors especially targeted at the str atified flow regimes encountered in horizontal wells. Independent, redundan t methods are used to measure the flow parameters and enhance the accuracy of the interpreted solution. This paper reviews new integrated production l ogging methods of evaluating multiphase flow in horizontal wells. Examples are shown illustrating the location and quantification of the flow profiles and fluid distribution in producing wells. This information allows effecti ve treatment of unwanted wellbore fluid entries. (C) 1999 Elsevier Science B.V. All rights reserved.