Theoretical Breakthrough Time of Vertical and Horizontal Wells Subject to External Fluid Drive in a Layered Reservoir with varying Architecture;Part VI:Letter‘H’Architecture

摘要

Theoretical breakthrough times for a vertically-stacked two layered reservoir with letter‘H’architecture and completed with vertical and horizontal well at the top and bottom layer,respectively,have been compiled.Both crossflow and no-crossflow interface cases were considered. Fifteen(15)different combinations of only edged fluid drive are possible.No bottom or top external fluid drive is possible for this architecture. Layered reservoirs with no-crossflow interface are characterized by functions viii(x),x(x)and ix(x) only.But when the two layers are contributing to flow through the interface,breakthrough times are identified by the function v(z),vi(z),viii(x),x(x)and ix(x)only. Theoretical breakthrough times derived were found to be directly proportional to reservoir extents in two(2)directions and inversely to reservoir layers diffusivity.Therefore,external fluid would finally reach the wellbores earlier if the fluid diffusivity is low and would be delayed if larger vertical reservoir areas are exposed to flow.The vertical reservoir area is suggested because of the infinite-acting boundaries bounding the upper and lower layers along the vertical axis.Irrespective of the number of sides of the reservoir and well type exposed to external fluid drive,the delay may be enhanced using perforation modification along the vertical axes or a rate selection based on estimated breakthrough time.Rate selection in the horizontal wells in this architecture is mandatory,since length modification is limited by lateral reservoir boundaries.