Cemented Completions and Through-Tubing Coiled-Tubing Drilling Enable Significant Cost Reduction in Mature Gas Fields
- Arian Ebrahimi (Wintershall)
- Document ID
- Society of Petroleum Engineers
- Abu Dhabi International Petroleum Exhibition & Conference, 12-15 November, Abu Dhabi, UAE
- Publication Date
- Document Type
- Conference Paper
- 2018. Society of Petroleum Engineers
- cement completion, coiled tubing drilling, cost reduction, ultra slim hole, underbalanced drilling
- 3 in the last 30 days
- 114 since 2007
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A novel well concept to unlock reserves from mature gas fields in Northern Germany has been developed. This concept combines cemented completions with through-tubing coiled-tubing drilling to enable significant cost reductions using ultra slim hole drilling in sour gas bearing, Upper Permian Zechstein dolomite reservoirs.
Once gas reservoirs mature, drilling of conventional infill wells can quickly become economically unattractive. Often this leaves resources untouched and it limits the economic life span of a field. To improve the economics of infill drilling in deep and mature gas fields significant cost reductions are necessary. These cost reductions can be achieved by changing the proven, yet costly, casing scheme to an ultra slim hole well concept. Besides unfavorable economics another challenge while drilling with conventional technology in mature fields can be the reduced inflow performance caused by formation damage. This challenge can be overcome by under- or at-balanced drilling, which is enabled by through-tubing coiled-tubing drilling.
Despite improved efficiencies gained from knowledge by drilling many offset wells, the estimated gas volumes are not sufficient to justify drilling of new wells with the established and conventional well design. Therefore, the operator prepared an advanced ultra slim hole well concept. The casing shoe setting depths remained unchanged, however the hole sizes are reduced significantly. The openhole reservoir section is changed from 5.875-in to 2.5-in and this section is drilled with coiled-tubing and through the installed completion. The size of the completion is selected to be 3.5-in and it is cemented in a 4.125-in hole. In this application, the cemented 3.5-in completion eliminates an entire 7-in liner that would be necessary in the conventional casing scheme. The remainder of the ultra slim hole well is drilled with a 5-in drilling liner, a 7-in intermediate casing and a 9.625-in surface casing. This needs to be compared with the conventional casing scheme comprising of an 18.625-in surface casing, a 13.375-in intermediate casing, a 9.625-in production casing and a 7-in liner. The reduction in cost is estimated to be in the order of 40%.
The presented concept can enable significant cost reductions and by applying this ultra slim hole concept further infill drilling in mature gas fields can become more economically attractive. Moreover, formation damage can be overcome by underbalanced drilling, which is enabled by drilling through-tubing with coiled-tubing. The synergies created by combining cemented completions with coiled-tubing drilling are presented in this paper.
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Almasmoom S., Gonzalez J., Ramos D., Al-Faraj O., 2015. A New Completion Approach in Saudi Aramco for Unconventional Gas Wells Using Full Monobore 4 1/2" Cemented Casing Completion. Presented at the SPE Saudi Arabia Section Annual Technical Symposium and Exhibiton held in Al-Khobar, Saudi Arabia 21-23 April 2015. SPE-177977-MS. https://doi.org/10.2118/177977-MS
Taoutaou S., Schreuder R., Bosma M., Schoenmakers J.Van der Vegt R., Stewart D., 2007 New Approach to Ensure Long-Term Zonal Isolation for Land Gas Wells Using Monobore Cemented Completion. Presented at the SPE Europec/EAGE Annula Conference and Exhibition held in London, United Kingdom, 11-14 June 2007. SPE-107433-MS https://doi.org/10.2118/107433-MS
Macfarlane M., Mackey P., 1998. Monobores-Making a Difference to the Life Cycle Cost of a Development. Presented at the SPE Asia Pacafic Oil & Gas Conference and Exhibition held in Perth, Australia, 12-14 October 1998. SPE 50046. https://doi.org/10.2118/50046-MS
Zerbst C., Al-Habsi H., 2013. Drilling and Completion Challenges for Deep, Tight Gas Exploration Wells Onshore Northern Oman. Presented at the SPE Middle East Unconventional Gas Conference and Exhibition held in Muscat, Oman, 28-30 January 2013. SPE-163977. https://doi.org/10.2118/163977-MS
Sheikj Veisi M., Salehpour A., Wedhaswari V., Bianchi N.Neto, Panjaitan R., An Innovative Approach to Cementation of Monobore Completion Tubing to Maximise Access to the Bottom Most Reservoirs. Presented at the IADC/SPE Asia Pacific Drilling Technology Conference held in Bangkok, Thailand, 25-27 August 2014. IADC/SPE-170476-MS. https://doi.org/10.2118/170476-MS
Leising J., Newman K., Coiled-Tubing Drilling. Presented at the SPE Annual Technical Conference and Exhibition held in Washington DC, USA 4-7 October 1992. SPE 24594. https://doi.org/10.2118/24594-PA
Faure A.. Horizontal Drilling with Coiled Tubing: A look at Potential Application to North Sea Mature Fields in Light of Experience Onshore, The Netherlands. Presented at the SPE Offshore Europe Confernece held in Aberdeen, Scotland, 7-10 September 1993. SPE 26715. https://doi.org/10.2118/26715-MS
Mix K., Bell G., Evans J. Coiled Tubing Drilling Case History. Presented at the SPE Gulf Coast Section/ICoTA North American Coiled Tubing Roundtable held in Conroe Texas, USA, 26-28 February 1996. SPE-36350-MS https://doi.org/10.2118/36350-MS
Pruitt R., Leslie C., Smith B., Knight J., Buchanan R. Sajaa Underbalance Coiled Tubing Drilling "Putting It All Together". Presented at the SPE/ICoTA Coiled Tubing Conference and Exhibition held in Houston, Texas, USA. 23-24 March 2004. https://doi.org/10.2118/89644-MS
Ebrahimi A., Schermer P., Jelinek W., Pfeil S., Pommier D., Flint G. Tubrodrill Bottomhole Assembly and Real-Time Data Improve Through-Tubing Coiled-Tubing Drilling Operations in Sour Gas Well. Presented at the ADIPEC Conference in Abu Dhabi, UAE, November 2015. SPE-177607-MS. https://doi.org/10.2118/177607-MS
Szary T., Pfeil S., Ebrahimi A., Balanced Thru-Tubing Coiled Tubing Drilling Unlocked Reserves in a Depleted Gas Reservoir in Northern Germany – Challenges and Lessons Learned From Two Pilot Wells. Presented at the 2011 DGMK/OEGW Spring Meeting in Celle, Germany, 2011. OIL GAS European Magazine 3/2011 ISBN: 0179-3187/11/III