The paper considers the disadvantages of existing blowout prevention equipment and provides the details of newly developed blowout preventer installed at wellheads of horizontal SAGD wells producing ultra-viscous oil. Several major challenges related to installation of existing preventers at wellheads of directional wells have been identified. These include the complexity, time-consuming and labor-intensive installation. Moreover, duration of preventer installation at high reservoir temperatures can be very critical in terms of personnel safety in case of gas, oil, water and steam kicks. In light of the above, appropriate choice and use of special blowout and well-kill equipment are very important factors. To address the above challenges, TatNIPIneft’s specialists have developed a blowout preventer with reduced overall dimensions and weight. The tool is adjusted to different sizes of backup flanges of wellhead assemblies of ultra-viscous oil wells in Tatneft PJSC. Implementation of the designed preventer improves safety of wellhead operations in directional wells producing ultra-viscous oil during well servicing and workover due to elimination of preventer performance degradation. This is achieved through reliable operation of sealing assembly irrespective of wellhead inclination angle. Apparent advantages of the preventer discussed in the paper include short installation time at inclined wellhead, small dimensions, reliability and versatility. The preventer has been tested at wellheads of seven directional wells producing ultra-viscous oil. The present research was included in the best practices of Tatneft PJSC.
References
1. Patent RU 2724695 C1, Preventer with replaceable ring and method of its installation on support flange of wellhead fittings, Inventor: Ziyatdinov R.Z.
2. Patent RU 2719884 C1, Preventer for wells
