Realization of the MonoDiameter Well: Evolution of a Game-Changing Technology

Abstract

Solid expandable tubulars have been used to assist in the success and slimming of deepwater wellbores over the past two years. The expandable openhole liner system expands and seals the outside diameter of an expandable casing against the inside diameter of a string of conventionally set casing, thus slimming the wellbore compared to conventionally cased wellbores. Further slimming of wellbores was realized with the capability of expanding and sealing sequentially installed expandable casing strings, or "nested" expandable liners. This procedure decreases reduction of a typical hole size by approximately 50%. Nesting was the next step in the evolution of creating a monodiameter system, that is, a wellbore that has the same inside diameter from surface to total depth (TD). The first nesting of two expanded casings in a well was successfully completed in a drilling application in the Summer of 2001, a milestone toward creation of the monodiameter wellbore. Using nested expandable systems facilitates the employment of smaller, more economical drilling vessels to drill deepwater wells (wells drilled in water depths of 1,500 to 10,000 ft). The monodiameter system is created when the junctions of the nested expanded casing liners are "over-expanded, resulting in a single internal diameter (ID) wellbore. This type of well exhibits the ultimate diametric efficiencies" a constant ID from the top of the well to its TD. The first monodiameter "over-expanded" sealed liner overlap was produced in the lab in late 2000, opening the door for the creation of the monodiameter drill liner, followed by the production-quality monodiameter liner system. This paper reviews the evolutionary steps taken to date toward the realization of true monodiameter technology and discusses the installations that have served as milestones. This paper also discusses the potential savings realized when wellbores are slimmed using expandable systems, combined with more economic drilling vessels and the associated reduced spread-rates. Technical Evolution Solid expandable tubular technology essentially changes how to install the main load-carrying member around which all well designs are built, namely, the casing. The monodiameter system became a feasible idea with the advent of successfully expanding solid tubulars. This revolutionary concept was proven with the successful expansion of solid tubulars (initially automotive steel) by forcing an expansion cone through the tubular with hydraulic pressure and expanding it ?20%. After demonstrating conceptual proof, attention turned to refining the existing materials to address specific downhole conditions. These developments consisted of replicating desired automotive steel properties in Oil Country Tubular Goods (OCTG), changing the cone material makeup from a combination of ceramic and steel to one of all steel, and replacing welded connections with specially threaded, expandable connections. L-80 casing was developed with exceptional fracture toughness in order to achieve consistent success of expansion without pipe body failure.

Solid Tubular Expansion in Horizontal Wells

“…Similar successful application of transforming conventional wells in mature basins to big bore producers using SET is reported in Malaysia [6]. Dupal et al [7] reviewed the evolutionary steps taken to date toward the realization of true mono-diameter technology and discussed the installations that had served as milestones. Brass et al [8] have reported the most recent successful application of using solid expandable tubular to shut off the water producing zones.…”

Tube Expansion Under Various Down-Hole End Conditions

“…SET technology has been implemented in a myriad number of situations since its first installation, with the intention to reduce operational costs and optimize the well delivery process not only as part of a contingency plan, but also as a fundamental component of the original drilling program. SET technology is currently known as a value-added, fit-for-purpose, and enabling alternative towards an effective drilling campaign (Dupal et al 2002;Carstens and Scrittmatter 2006).…”

“…A review of selected literature on down-hole tubular expansion (Cales et al 2001;Dupal et al 2002;Mack 2005;Carstens and Scrittmatter 2006;Binggui et al 2009) shows that most of the research and development work was carried out mainly by technology deployment companies to find short term and problem specific solutions. The experience of field engineers and a few simple lab trials were mainly instrumental in devising solutions without having substantial theoretical basis and appropriate scientific validation.…”

“…The experience of field engineers and a few simple lab trials were mainly instrumental in devising solutions without having substantial theoretical basis and appropriate scientific validation. The pioneering work of (Filippov et al 1999) presented three feasible scenarios of SET technology including openhole liner, cased-hole liner, and expandable liner hanger systems. Mack et al (1999) identified the chemical composition of expandable steel tube of grade L-80, and conducted an experimental study to determine the effect of expansion on its mechanical properties.…”

Post-Expansion Characterization of ExpandableTubular: Progress and Challenges

“…The dream of having a mono-diameter well is still not possible in foreseeable future. A review of selected literature on Solid Expandable Tubular [1][2][3][4][5][6] shows that most of the research and development work were based on finding fit-for-purpose solutions for specific field problems. Experience of field engineers and few simple lab trials were mainly instrumental in devising a solution without having substantial theoretical basis and an appropriate scientific validation.…”