Publications

A study (JIP) on reliability of well completion equipment (“Wellmaster Phase III”) was completed by SINTEF in November 1999. This has resulted in a comprehensive database on well completion equipment, with a total of 8000 well-years of completion experience represented and more than 1000 downhole failures included, given as input from the 16 funding oil companies of this JIP. The database represents all categories of downhole equipment, from tubing hanger level down. The paper points towards the major contributors to well interventions and downtime, indicating industry average and benchmark failure rates of the most vital completion components. A historical evolution in reliability of Subsurface safety valves (SCSSV) is demonstrated, and the industry wide effect of reliability improvements is shown through specific examples. In the North Sea, reliability data has gained widespread acceptance for use in decision making. The paper lists several cases where reliability data of downhole equipment has been used with a major impact on field development and subsequent operational expenditures.

This document provides an overview of available reports and publications from ExproSoft and SINTEF on subsea and downhole equipment reliability.

Molnes, E., Sundet, I. 1995: “Reliability of Well Completion Equipment - Phase II. Main Report”. SINTEF Report STF75 F95051.

This report describes the results from the project ”Reliability of Well Completion Equipment - Phase III.

The project has been funded by 16 oil companies, and reliability data has been collected and analysed for a total of some 1600 wells located all over the world. The Windows-based dedicated software and database (WellmasterTM v2.5) is improved to include specialized completions. Wellmaster version 2.5 is a 32-bit program with improved performance under Windows 95 and Windows NT. The functionality of the program has been extended to include multilateral completions, monobore completions, x-mas trees and other features. In addition, a new internet software package (WellWatch) has been developed to make failure data more accessible, and to motivate the participants (and vendors) in establishing more detailed failure descriptions.

Key reliability figures are presented for the major items in well completions, with emphasis on the main safety item such as the safety valve (SCSSV).

This report documents the main findings from the research project “WellMaster: Reliability of Well Completion Equipment – Phase IV”. The project objective has been to contribute to improvement in completion equipment reliability through systematic collection, analysis and feedback of reliability data to participating oil companies and equipment manufacturers. The WellMaster database is currently the most comprehensive completion equipment database worldwide, with participation from 13 major oil companies in Phase IV. Key figures on the database scope are:

-More than 102.000 completion string items represented in equipment database
-A total of some 1.400 equipment failures included for a total of 5 different completion equipment categories
-A total of 2.229 wells with 2.702 completions are included, representing a total of around 11.500 completion-years of experience

The report presents details on database scope, reliability trends and failure data on all major completion equipment items with emphasis on surface controlled subsurface safety valves (SCSSVs). Detailed data are also presented on other vital downhole equipment such as electrical submersible pumps, permanent gauges, tubing and intelligent completion items.

This report presents the results derived from the joint industry project “SubseaMaster: Experience database for subsea production systems – Phase II”.

The project phase was funded by 5 oil companies, and reliability data is collected and analysed for a total of some 50 subsea wells including 14 associated manifolds and lines located in the Campos Basin, the Gulf of Mexico, and the North Sea. The Windows-based dedicated software and database (SubseaMaster) is upgraded based on data collection experiences and feedback received during software training and project meetings. SubseaMaster version 2.0 is a 32-bit client/server program utilising Oracle database and SQL Net with improved performance under Windows 95/98/NT/2000/XP. The functionality of the program is extended to include installation/retrieval failures, resident equipment failures, top tension riser systems and subsea control module internal items, and other.

Key reliability figures are presented in this report for the major items in a subsea production system with particular emphasis on the main safety items such as the X-mas tree master and wing valves.