MODU Drilling Rig Downtime: An Objective Analytical Approach

Abstract

SPE and IADC Members Abstract For the past 2 1/2 years and over 250, 000 MODU operating hours, which included up to 8 floating drilling rigs and 17 bottom sitting drilling rigs, downtime data was inputted into a defined matrix for analysis. By use of 6 categories (drilling, subsea, mechanical/electrical, etc.) and 5 causes (operation, manufacturer/warranty, maintenance, etc.) of downtime a 6 by 5 matrix was developed to pinpoint fleet wide as well as individual rig pinpoint fleet wide as well as individual rig problem areas. Downtime data was inputted into the problem areas. Downtime data was inputted into the computer weekly as well as accidents, lost time accidents, rig status and "flags" of interest that include up to 100 different printout options. Each downtime incident has a succinct description with corresponding corrective action. The system has proven objective, useful in spotting problem areas, proven objective, useful in spotting problem areas, and with its strict definitions very repeatable. With the aid of the downtime system and reinforcement by the companies Preventative Maintenance Program, downtime LTA's and accident rates have all decreased. Introduction For years Drilling Contractors have tried to keep and show downtime statistics for internal as well as external (customer) use. Downtime can be highly interpretive and subjective with results historically dictated by the anticipated end use. For example there is contract downtime", "operating downtime", "trouble time", etc. all of which when evaluated give drastically, non-comparable results. To avoid biased, favoritism or subjective analysis requires a clear, definitive definition of rig downtime. The brief definition of downtime is non-productive operating time caused by equipment and/or personnel failure either by the contractor, operator or third parties- This paper will define downtime and how contractor downtime incidents are classified. The paper will discuss usage of the computer to manipulate the data and present several output and trend analysis curves. Finally this paper will examine uses of the information along with the authors conclusions. DOWNTIME DEFINITION If the rig is delayed from conducting normal operations due to personnel or equipment failure then downtime has occurred and should be included in the database. Five major exceptions are:Preparing for a hurricane, evacuation, and time spent putting the rig back in operation is not included in any way in the database.Fishing for downhole tools/tubulars regardless of the cause is not considered downtime.Circulating out a kick is not considered downtime.Waiting on cement is also not considered downtime.Other problems that are not caused by equipment or personnel directly. Contractor and Non-Contractor downtime is listed. The entire scope of time is listed for each incident not just the repair time. If a repair requires pulling up into the casing, making a repair and tripping back to bottom, then the incident's time would include that short trip.