Advances in Expandable Tubing – A Case History

Abstract

The paper describes the world's first use of expandable solid tubing to close off perforations. The development and testing of the system leading up to the two field installations is described with the execution and validation process. The fundamental concept of solid tubular expansion had been proven to be sound, but four main development hurdles needed to be overcome. Extensive innovation in design and material selection culminated in two main applications being fulfilled, with subsequent testing proving the absolute success of the technology. These first few steps pave the way to a number of existing commercial applications and our ultimate goal of mono-diameter wells. Introduction Solid tubular expansion technology is the downhole process of expanding the diameter of pipe in situ by means of pumping or pulling a mandrel through it. There are a number of applications for the technology1,2,3,4. One such application is to repair casing and shut-off unwanted fluid entry. The main advantage of using this technology as opposed to conventional means is that it can restore the casing to its original integrity without a significant loss in internal diameter. Methods used previously, such as casing patches or packer straddles, result in severe inside diameter restrictions and have suffered from leaks in the packer or the patches. Expandables were thus seen as a potential innovative breakthrough. Shell U.K. Exploration and Production (Shell Expro), operating in the U.K. sector of the North Sea on behalf of Shell UK Limited and Esso Exploration and Production UK Limited, has been actively involved with the development of solid tubular expansion from the start, and has been working closely with e2 TECH. This was to maximize the learning value and to obtain early experience with the technology prior to its use in their high cost offshore environment. A structured, step-wise approach to technology implementation was followed. Testing the system in test wells was included, both vertical and horizontal, up to a depth of 2,400 ft to fully prove the system in a lower cost land operation prior to the high cost offshore environment of Shell Expro. The fundamental concept of solid tubular expansion had been proven to be sound, but besides the actual expansion process, there were a number of hurdles that needed to be overcome. Among these were (a) to source a suitable pipe material and (b) design connections that are able to withstand the expansion ratios and meet the requirements such as burst and collapse, (c) an anchor and (d) sealing system. Concepts were conceived, developed and tested and many challenges overcome which led to the successful installation of four systems in producing wells. Using a work-over hoist, perforations in both oil and gas wells were sealed off and a clad was installed to act as a shroud for an ESP. Not only did the solutions solve the operators’ problems and increased production, but due to the characteristics of some of the wells, allowed the systems to be tested much more rigorously than would normally have been carried out. Methodology Overview Due to the technology being in its infancy a number of core technologies had to be demonstrated. These were developed with the upcoming application in mind. The design process can be split into two separate design areas. Firstly, the liner system; this is the part that completes the well, consisting of the expandable liner and sealing / holding mechanisms, cone launcher and connections. Secondly, the ‘deployment system’ area; considered the more traditional set of tools, e.g. temporary anchor, disconnect mechanisms, load sub and the expansion mandrel.

Indirect Extrusion: A Multifaceted Approach of Sub-surface Tubular Expansion

“…Due to this, one can reach the reservoir with adequate production hole sections at total depth, hence will avoid adverse effect on oil production. Ruggier et al [29] have documented the advances in expandable tubing for zonal isolation and casing repair. The main advantage of using expandable tubing as opposed to conventional means is that it can restore the casing to its original integrity without a significant loss in internal diameter.…”

Expandable Tubing R&D on the Material of FMA Multiphase Alloy Steel

“…According to the invariability of oil reserves, it becomes the most important way of improving petroleum supply to increase drilling technique and reduce drilling costs. Expandable tubing technology which to reduce oil drilling costs is known as the "21st century core technology of oil drilling industry" [1] , the technology arousing widespread concern in industry area.…”

A Method for Isolating Pressure-Depleted Zones With Solid-Expandable Tubulars

“…[1][2][3][4][5][6] The scoping mechanism in SET expansion occurs initially in all SET installations. Hydraulic pressure in the cone launcher forces the expandable tube downward across the upward-facing cone for several feet until the cone launcher contacts the bottom of the hole.…”