|
|
Technical Paper: Multilevel Injector/Producer Wells in Thick Heavy Crude Reservoirs
Paper 53950
Abstract
With modern drilling techniques it is now possible to drill wells with multiple branches emanating from the same vertical or even horizontal trunk. Several heavy crude reservoirs are very thick and had they contained light crudes, their vertical permeability could make them attractive for single horizontal wells. Unfortunately, the much higher viscosity of the reservoir fluid results in highly unfavorable mobility. Thus, drilling several horizontal branches at different levels of the reservoir would effectively create thinner drainage areas and this, in itself, would be attractive because in thin reservoirs the vertical mobility is far more forgiving. However, a clear benefit in heavy crudes is derived from thermal recovery and a scheme is suggested here, where either steam is injected at the top of the reservoir or hot water is injected at the bottom through a dedicated horizontal well injector. (From an operational point of view it is desirable to use the same vertical trunk for both injection, e.g., through the tubing and production through the annulus, or vice versa.) The optimization strategy is to estimate the desirable number and spacing of the producing laterals. The vertical spacing is not even, but instead, it depends on the crude oil viscosity, that, in turn, is affected by the heating process. We present in this work a methodology of multilevel well optimization and several case studies for different numbers of laterals and their vertical spacings.
This page contains additional information that requires a premium content account to view. Sign in to view the rest.
|
|
|
