DEVELOPMENT OF PROJECT DOCUMENTATION FOR WELL CONSTRUCTION WITH THE USE OF MPD TECHNOLOGY

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In traditional drilling technology, in order to prevent gas and oil-water blowouts, the pressure in the well should exceed the reservoir pressure by 5–10 % in static conditions, depending on the depth. However, in case of catastrophic sinking, drilling of highly permeable formations, narrow drilling windows in zones of abnormally high pressures such a safety method, on the contrary, often makes it impossible to drill the well. Today there are special systems to control the pressure in the well during deepening and circulation stops for drilling in difficult geological conditions. Their work is based on high-precision control of pressure in the annulus and its regulation at the sealed wellhead by means of an automatic choke in combination with a Coriolis flow meter. In static conditions, the required pressure is maintained either by an additional pump or by a nitrogen injector.Development of well construction projects requires reference to industry specific normative documents regulating the methodology of work, equipment selection and defining the minimum list of other technical and technological solutions necessary for quality and safe drilling operations. However, despite the fact that the technology of drilling with controlled pressure in different variations has been used in Russia for twenty years, there are still no regulatory documents summarizing the entire domestic experience of its application and regulating the procedure of drilling operations with controlled pressure. Their absence leads to certain technical risks and difficulties in passing departmental expert reviews of project documentation.This article analyses the rules and recommendations for well construction using managed pressure drilling technology contained in national industry regulatory documents, highlights the problems arising in the development of the technical part of the design and estimate documentation for the construction of similar wells, and gives recommendations on the composition of a regulatory document that could summarize national and foreign experience of managed pressure drilling.