Criteria and risk of integrity loss for wells with sustained casing pressure

• Autorzy: Yao T. , Wojtanowicz A.

Identyfikatory

DOI

10.7494/drill.2017.34.2.639

• Języki publikacji: EN

Abstrakty

EN

Sustained casing pressure (SCP) represents a major issue because of its large scale occurrence and risks to health, safety, and the environment. Present regulatory assessment of sustained casing pressure is mostly qualitative with implicit risk formulation. It currently holds that wells with casing head pressure that can be bled-down to zero and is followed by slow 24-hour pressure buildup are below acceptable level of risk. This study introduces new quantitative metrics of well integrity loss risk - the instant cement sheath leak rate of 15 scf/min (barrier integrity), and the total annual environmental gas discharge of 6 tons of volatile organic compounds (VOC) per year. Field data from 19 wells reportedly affected by sustained casing pressure (SCP) are examined with a SCP testing software to assess whether or not wells with pressure that is able to bleed to zero would meet the proposed criteria. Using modeling and software tools developed by Xu and Wojtanowicz (2001) and Kinik and Wojtanowicz (2011), it is determined that three of the 19 wells (15.8) examined would fail the instant leak rate criterion. On the total discharge criterion, assuming the wells' annuli above the cement top filled out with seawater, it was also found, again, that 15.8 percent of the wells would fail the total environmental discharge criterion. Moreover, for the worst-case scenario of absolute open gas flow (empty annulus above the cement top), five of 19 wells (26.3) would fail the criterion. It is shown that - statistically, the bleed-down of casing pressure to zero gives a 90-percent confidence of the well passing the proposed criteria. Furthermore, no clear correlation was observed between pressure build-up and the barrier integrity or the environmental gas discharge criteria, thus questioning the 24-hour pressure buildup relevance as a risk indicator.

Słowa kluczowe

EN

well integrity; gas migration; sustained casing pressure; environmental risk

• Wydawca: AGH University of Science and Technology Press
• Czasopismo: AGH Drilling, Oil, Gas
• Rocznik: 2017
• Tom: Vol. 34, no. 2
• Strony: 639--654
• Opis fizyczny: Bibliogr. 16 poz., rys., tab., wykr.

Twórcy

autor

Yao T.

• US Department of Energy

autor

Wojtanowicz A.

• Louisiana State University

Bibliografia

• [1] 30 CFR Part 250.519-531: Casing Pressure Management U.S. Code of Federal Regulations.
• [2] 40 CFR Subchapter C Part 60 Subpart OOOO: Standards of Performance for New Stationary Sources. U.S. Code of Federal Regulations.
• [3] Al-Tamini A., Al-Mansoori S., Samad S., Al-Shagga M., Hussain A., Ghneim G.J., Sakkaf A.: Design and Fabrication of a Low Rate Metering Skid to Measure Internal Leak Rates of Pressurized Annuli for Determing Well Integrity Status. 2008 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, United Arab Emirates, 3-6 November 2008, SPE-117961-MS.
• [4] API Recommended Practice 90: Annular Casing Pressure Management for Offshore Wells. API Publishing Services, Washington, D.C., 2006.
• [5] API Recommended Practice 14J: Recommended Practice for Design and Hazards Analysis for Offshore Production Facilities. API Publishing Services, Washington, D.C., 2013.
• [6] Bourgoyne A., Scott S., Manowski W.: A Review of Sustained Casing Pressure Occurring on the OCS. Minerals Management Service, Washington, D.C., 2000.
• [7] Bourgoyne A.T., Millheim K.K., Chenevert M.E., Young F.S.: Applied Drilling Engineering. 1st ed. Society of Petroleum Engineers, Richardson, TX, 1986.
• [8] Huerta N.J, Checkai D., Bryant S.L.: 2009. Utilizing Sustained Casing Pressure Analog to Provide Parameters to Study CO2 Leakage Rates Along a Wellbore. SPE International Conference on CO2 Capture, Storage, and Utilization, San Diego, California, USA, 2-4 November 2009, SPE-126700-MS.
• [9] Josey R., Hoshman R., Patton, F.: Investigation of Blowout Main Pass Block 91 OCS-G 14576. Minerals Management Service Gulf of Mexico OCS Regional Office, New Orleans, LA, 2008. (August 23, 2007).
• [10] Kazemi M., Wojtanowicz A.K.: Development of Improved Testing Procedure for Wells with Sustained Casing Pressure. SPE Annual Technical Conference and Exhibition, Amsterdam, The Netherlands, 27-29 October 2014, SPE-170693-MS.
• [11] Kinik K., Wojtanowicz A.K.: Identifying Environmental Risk of Sustained Casing Pressure. SPE Americas E&P Health, Safety, Security, and Environment Conference, Houston, TX, USA, 21-23 March 2011, SPE-143713-MS.
• [12] OLF 117 Norwegian Oil and Gas Recommended Guidelines for Well Integrity. Norwegian Oil and Gas Association, Stavanger, Norway 2011.
• [13] Rocha-Valadez T., Hasan A.R, Mannan S., Kabir C.S.: Assessing Wellbore Integrity in Sustained-Casing-Pressure Annulus. SPE-169814-PA, 2014.
• [14] Weaver J.L.: Offshore Safety in the Wake of the Macondo Disaster: The Role of the Regulator. Houston Journal of International Law, 36 (379), 2014, pp. 124.
• [15] Xu R., Wojtanowicz A.K.: Diagnosis of Sustained Casing Pressure from Bleed-off/Buildup Testing Patterns. SPE Production and Operations Symposium, Oklahoma City, Oklahoma, 24-27 March 2001, SPE-67194-MS.
• [16] Zhu H., Lin Y., Zeng D., Deping Z., Feng W.: Calculation analysis of sustained casing pressure in gas wells. Petroleum Science, 9 (1), 2012, pp. 66-74.

Uwagi

EN

This article is written in the author’s personal capacity, and does not necessarily represent the viewpoints or perspectives of the Department of Energy or the Federal Government

PL

Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę (zadania 2017).