Landing String: Breaking the 2.5 Million Pounds Limit

Abstract

Abstract Landing heavy casing strings, which operating companies run in nowadays deeper prospects, is challenging and numerous papers have covered some aspects of the solutions used in these world class operations. To date most of these papers (Brock and al. 2010) (Chandler and al. 2012) cover casing landing application running up to 2.5 million pounds (1,250 sTon), which is the hoisting capacity of most offshore mobile drilling units. A trend is well established in the industry with more frequent requests for landing strings of higher tensile capacity for which designs exist with ratings of 2.75 or even 3.0 million pounds. Reaching this level of tension in a string is demanding in terms of its own design and also brings additional challenges when it comes to hoisting it on the rig, sitting it on slips, torquing it, being able to shear it with BOP in the event that quick disconnect is required. Our group of authors covers these various aspects in this paper that addresses the impact of design choices and details the industry's best options for every landing string interface. Often, the system components are selected in isolation bringing partial answers to this industry challenge; the true answer goes beyond this and is an integrated solution. This paper presents an array of technologies, which allow operating companies to safely run casing strings weights in excess of today's standard and could serve as guidelines for drilling engineers when they plan deeper frontier prospects.