An Integrated Study of Water Coning Control with Downhole Water Sink Completion Approaches in Multilayered - Strong Water Drive Reservoir to Improve Oil Recovery

Abstract

A reservoir with bottom water drive mechanism has a high tendency to generate water coning effect in their production life. As a result of water coning phenomenon, the well has a low critical safe rate which limits the productivity of the reservoir. Consequently, a new innovation for completion design in an oil well with a bottom aquifer drive is needed. The author offers a Downhole Water Sink (DWS) system to solve this problem. DWS is a dual completion design innovation where two tubing strings are installed into the well to produce both water and oil simultaneously by different tubing. The main principle of DWS is to create a stable pressure drawdown in oil and water zone so that a stable oil-water contact is formed. DWS application in a multilayered reservoir expected to be able to resolve the water coning phenomenon thus the recovery factor increased and the well becomes economic to be produced. In this paper, the study approach involved by numerical simulation within IMPES methodology (Implicit Pressure Explicit Saturation) and Thomas’s algorithm to solve iteration. Completion modeling is creating two wells on the similar coordinate in several layered reservoirs aims to produce oil and water separately on tubing on the well. The percentage of water cut on oil production tubing is 0% while the percentage of water cut on water production tubing is 100%. This thing shows that DWS completion system will give a greater cumulative oil production in a high production rate and the oil is oil-free water. It is observed that the successful implementation of DWS in a multilayered reservoir is taken place. The well with DWS design configuration for the WDP system shows a better performance of oil productivity compares to a conventional well completion design. This result is supported by no water production observed at oil production tubing on the surface well level. There are some parameters that affect DWS system application modeling i.e. mobility ratio, vertical and absolute horizontal permeability (kv & kh) also perforation interval. Down-Hole Water Sink is an appropriate innovation to eliminate water coning and producing oil with high recovery factor. DWS application in a multilayered reservoir with bottom aquifer driving mechanism shows a better performance of oil productivity compares to a conventional well completion design. This result is supported by no water production observed at oil production tubing on the surface well level.