Three Diverse Applications on Three Continents for a Single Major Operator
Authors: Sanders Tom , Baseflug Tim , Keith Neal 
Published: October 2008

Solid expandable tubular technology has achieved gradual acceptance in diverse regions worldwide since its commercial introduction over four years ago. Although there is still reluctance among operators to commit to preplanning this technology in their wells, others recognize the value of using solid expandable tubulars on a contingency basis. These innovators are embracing it as a method not only to overcome challenges and achieve the well objectives regardless of environmental circumstances but to achieve these goals using an economically viable, repeatable method.

Recently an operator with wells in three different challenging regions of the globe deployed solid expandable tubular technology in each well. In West Africa, the requirement was to isolate a casing leak and return a damaged well to production. The challenge in the Asia Pacific region was to drill a deepwater exploration well using surface stack deepwater drilling technology. In Texas, the operator isolated ballooning shale so that the 7-in. conventional casing could be set at target depth to retain projected hole size. In diverse challenges, solid expandable tubular technology provided the operator viable, value-driven options that were not available using conventional casing and technology.

This paper will present the challenges one operator faced in three global regions, discuss how solid expandable tubular technology overcame the challenges presented by these environments, and created an economically-viable solutions. The diversity of solid expandable tubular technology as it continues to gain acceptance within the oil and gas industry will be also demonstrated.

Introduction

Oil and gas exploration is one of the most expensive undertakings in the world today and operators of oil and gas companies are, by nature, a conservative group. Known technologies that have been tried, tested, and proven to be successful and repeatable are the solutions most operators choose when faced with downhole challenges. When a new technology emerges as an alternative to conventional equipment, many operators are unwilling to embrace the new technology. The perceived risks are too great and jeopardizing their expensive investments as a "testing ground" is not acceptable. Those operators are prone to use known technology to overcome well challenges even though the conventional method may cost more money.

Solid expandable tubular technology is but the latest advance in the way wells are drilled and completed that has faced operator skepticism. Few want to be a guinea pig for a technology that could incur additional financial costs above and beyond the capital assets already laid out.

The basic principle of solid expandable tubular technology is cold-drawing steel tubulars to the required size downhole. An expansion cone mechanically deforms the pipe permanently. The cone moves through the tubular by a differential hydraulic pressure across the cone itself and/or by a direct mechanical pull force. The bottom-up movement of the cone through the tubular deforms the steel past its elastic yield limit into its plastic deformation region (Fig. 1). Expansions of over 25%, based on the inside diameter (ID) of the pipe, have been accomplished. Most applications, however, require expansions of less than 20%.