Abstract
Horizontal wells are superior over conventional wells in terms of production improvement due to increased reservoir contact. Despite this, these wells pose severe production challenges due to variations in permeability, reservoir pressure, reservoir fluid properties and frictional pressure drop along horizontal section. Preventing water/gas breakthrough, equalizing inflow with minimizing pressure loss, minimizing annular flow and heel-to-toe effect, delay non-uniform water progress, avoiding by-passed oil, increasing sweep efficiency and ultimate recovery are some of the primary challenges for gaining optimum advantages of horizontal wells. One of the promising technologies to address all these challenges is the application of advanced completions utilizing Passive inflow control device (ICD) with oil swellable packers.
The use of Passive Inflow Control Device (ICD) along with oil swellable packer in long horizontal wells drilled in unconsolidated sandstone reservoirs has helped alleviate premature water breakthrough /high water production and sand production. Passive inflow control devices (ICDs) are effective in terms of balancing production flow and delaying the onset of water production. Nevertheless, when gas and/or water breakthrough occurs, a passive ICD will allow production of the unwanted fluid along with usual production.
This paper discusses the detailed of Passive ICD design workflow and execution carried out to complete 6 nos. of horizontal wells of Oil India Limited in a reservoir having active aquifer drive considering challenges encountered due to uncertainty in permeability, water saturation, permeability distribution and saturation tables distribution. In the absence of dynamic reservoir analysis, offset well data analysis assisted in filling the data gaps by enabling geological and reservoir level understanding. The passive ICD were designed on the basis of Gamma Ray, Resistivity, NPHI (Neutron Porosity Log) and RHOB (Density Log) obtained during TLC logging. A Geological Model was constructed with certain gathered data and few Assumptions were made to obtain reservoir saturation and permeability. Moreover, in this paper an assessment is provided of the production performance review conducted over unconsolidated sandstone reservoirs developed with some horizontal wells equipped with Passive ICD completions compartmentalized with oil swellable packers versus other horizontal completions completed with conventional slotted liner completions.
As drilling and completion of horizontal wells are expensive, it was critical to identify the most-suitable Passive ICD completion design with the available dataset before attempting well completion. This was addressed through a customized workflow to design and compartmentalized the horizontal section utilizing the ICD and oil swellable packers for maximizing oil recovery and water/sand breakthrough problem elimination.
