Abstract
Companies engaged in the exploration and production of oil and gas in the North Sea very often face problems that arise when drilling salt formations. In this Thesis, drilling through Zechstein will be considered. In addition to the conventional problems that arise when drilling salt layers, there is the problem of floaters, uplifted or detached carbonate blocks on the flank of a tectonized fault zone. It was proposed to use managed pressure drilling (MPD) during drilling of these intervals. Accordingly, it is necessary to assess the feasibility of using this technology in such problematic areas. Project N is a development horizontal offshore well in the Netherlands in the North Sea operated by Wintershall Noordzee B. V. First of all, the basic information of a selected well will be presented. The geology of the section of interest will be described in detail, problems that may occur during drilling are identified. Also, seismic issues will be addressed, the probability of accurately determining the location of the floaters is estimated. Secondly, a general review of MPD technology, its categories, and variations, will be carried out. Attention is drawn to the use of MPD for drilling salt layers in the past. The basic MPD equipment is described, the availability of the platform, the use of which is planned in the project, for MPD is estimated. Besides, the stability of the wellbore largely depends on the mud program of the drilling process. Casing and cementing issues are also covered. The main problems that may interfere with the normal and reliable performance of these operations are identified. As a result, casing and cementing programs as well as their solutions are described in detail. For different problem interval drilling scenarios, the feasibility of using MPD is described, and for the case where the use of MPD is necessary, MPD Influx Management Matrix is developed. An important point is the economic component of this technical solution. Both the use of the MPD and the financial consequences of its non-use are estimated, as a result, the economic effect is obtained. After a detailed analysis, it was found that the use of MPD in this region is appropriate. Firstly, it was proved that without additional expensive geological studies it is impossible to determine exactly the presence of floaters. Secondly, when considering various scenarios, it was found that when encountering floater and subsequent kick of averaged intensity, the conventional drilling system is not able to stabilize the well, while the MPD allows safe drilling of the hazardous interval. Thirdly, the economic effect of the use of MPD plays an important role in the final solution. The use of MPD requires an initial investment, but the consequences of not using MPD in an influx situation far exceed these costs. Thus, the use of MPD in this section would help to save a lot of money and time and therefore is a suitable technical solution.
Translated title of the contribution | Anwendung der Managed Pressure Drilling (MPD) Technologie im Projekt N auf dem Nordseeschelf |
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Original language | English |
Qualification | Dipl.-Ing. |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 22 Sept 2020 |
Publication status | Published - 2020 |
Bibliographical note
embargoed until nullKeywords
- Drilling Engineering
- Offshore Drilling
- Managed Pressure Drilling
- North Sea