Production Optimization of Multi-Lateral Wells Using Passive Inflow Control Devices

Abstract

Abstract Passive ICDs (Inflow Control Devices) are being used to enhance performance of horizontal wells in unfavorable environments such as non-uniform permeability and/or pressure variations along horizontal sections. This is the first ever attempt, to the best of our knowledge, at using ICDs to manage inflow from two laterals connected to a motherbore. Furthermore, this well is a 3 7/8" openhole multi-lateral with a 2 7/8" ICD completion. This paper presents how passive ICD completion technology is used to optimize well productivity in a multi-lateral well. This carbonate well was sidetracked to increase reservoir contact and create the required multi-lateral. Subsequently, the ICDs were run, and to confirm the inflow profile along the length of the of the ICD completion, a PLT survey was conducted. The actual rate and inflow profile compared favorably with the predictions as per design of the ICD completion. This paper will show the well design, the actual PLT vs modeled results, and discuses future utilizations for this technology. The key factor in the success of this project was the use of the 2-7/8" ultra-slim ICD completion, which was optimized based on numerous wellbore hydraulic simulations, to determine the appropriate number of ICD units and compartments to balance the required off-take from each lateral, and from individual compartments in the motherbore section. Introduction Horizontal multi-lateral wells have been used globally to enhance reservoir contact and ultimately improve well performance1. Variations in permeability, reservoir pressure, reservoir fluid properties, and frictional pressure drop along horizontal sections, can create non-uniform inflow profiles, which can lead to early breakthrough of water or gas in reservoirs with an aquifer and/or gas cap. Breakthrough typically occurs in regions of high permeability or at the heel of the lateral section in homogenous reservoirs. This ultimately leads to a reduction in reserve recovery and well performance. The use of ICD completions to effectively manage non-uniform inflow profiles has been described in past publications2. In this completion, ICD's were used to control the inflow from two laterals and along the motherbore. Background The subject well was originally drilled and completed as an open hole vertical oil producer in 1966. By 1977, the well had developed a casing leak and consequently, a 4½" liner was run to isolate the leak. Initially, the well produced 5 MSTBD dry oil. Water production began in 1998 and it reached 50% water cut by the end of 2007; consequently, the well was plugged back to within 20 feet from the top of the reservoir to minimize water production; however, it was with limited success. Due to continued water production, the well was worked over in 2008 and converted to a tri-lateral well with 3-7/8" short radius horizontal laterals to acess the top 20 ft of the reservoir allowing continued recovery of dry oil.