Cost of Abrasive Cutting in Decommissioning Operations in the Gulf of Mexico

Abstract

Mechanisms that inject cutting materials into a water jet and abrasively wear away steel/concrete are called abrasive cutters. The purpose of this paper is to model the cost of abrasive cutting operations associated with decommissioning offshore structures in the Gulf of Mexico. The elements of a standard abrasive cutting contract are presented and the total cost of a job is derived based on the parameters of the contract. The total cost to perform a severance operation is aggregated according to job type and normalized according to the number, size, and length of cut performed. Descriptive statistics are provided based on data collected over a three-year period from 2000–2002, and relations are derived that estimate the time and cost of a cutting operation based on various descriptor variables. A major conclusion of the analysis is that abrasive cutting is a structure-independent operation, or in other words, the total cost of performing the service does not depend on the characteristics of the structure and can only be predicted after the job is finished and the on-site time of the cutting crew is known. This is in sharp contrast to explosive cutting, where structural characteristics are very good indicators of job cost.