Abstract

Intelligent and multi laterals wells are evolving as key completion technologies to enhance and maximize hydrocarbon recovery. A pre-requisite for the successful application of multi lateral and intelligent well systems is zonal isolation and compartmentalization of the reservoir. Current Techniques either involve the cementing of the mother-bore and/or the use of complex mechanical systems and packers to isolate individual zones. Both techniques increase the complexity of the operation and result in reduced ID from the additional casing string. In addition with intelligent well systems, a feed through system for the hydraulic, electrical or fiber optic cable must be used across the isolation device. This join or break represents another weak link or potential failure point in the system.

An isolation device has been developed which uses a rubber elastomer bonded onto a base pipe. The rubber swells in hydrocarbon and provides an effective seal down hole between the base pipe and the openhole to maintain zonal isolation in even the most complex environments. Any number of packers can be made up in the completion string to provide the zonal isolation required and are run as an integral part of the completion string in a single trip.

The swell packer offers many advantages over conventional techniques, besides it simplicity it is able to conform to irregular wellbores, the system can seal in open hole eliminating the need for a completion liner for zonal isolation. This saves rig time and money in the completions and allows for larger ICV's to be run. In addition, the use of a unique feed through system allows control lines and fiber optic cables to be run through the packer without a connection or splice at the packer. This paper will describe recent case histories and planned operations in Saudi Aramco where the swell packer has enabled intelligent completions, multi lateral, and reservoir compartmentalization for equalizer completions and simplified the process of cable feed through on intelligent completions.

1. Background

Aramco has successfully utliized both horizontal and MRC wells (multi lateral with greater than 8km of reservoir contact) to enhance and maximize hydrocarbon recovery from its reservoirs. In recent years, the intergration of both intelligent and passive inflow control completion systems have further enhanced the value of MRC well by providing inflow control, better inflow profiles, and downhole monitoring capabilities.

Saudi Aramco's first intelligent well completions were drilled as 7″ fullbore wells. A cemented 7″ liner was placed below the conventional 9–5/8″ casing provided the lateral isoallteion and a means to conventionally drill the TAML level two multi lateral wells. Standard 3–1/2″ ICV's and mechanical packers were used to provide the required intelligent well completion. (see figure 1.)

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