Bit and bottomhole assembly (BHA) dynamics are a challenge when drilling in hard and interbedded formations. Dynamic conditions such as stick-slip and whirl can limit performance or in the worst case destroy downhole components. A new percussive mud hammer motor is being implemented in China to improve drilling performance by imparting a controlled impact to the bit while drilling. Conventional technologies to address these challenges may have limited improvement significant added costs: Conventional motors can generate large amounts of torque to the bit but can be difficult to control tool face and depth of cut as the bit transitions through various formations. This can result in stick-slip and bit bounce that can quickly damage or destroy the bit and BHA. Rotary steerable systems can control downhole dynamics with complex electronic, hydraulic and mechanical components but are very expensive, require higher system pressures and on-site supervision. Turbines with impregnated diamond bits can provide smooth drilling but can have limited rates of penetration in the softer portions of interbedded formations. In operation they also require higher pressure drops, have limited build rates and require on-site supervision by a turbine technician. These conventional system limitations created an opportunity for a new technology that is simpler and brings greater value to the drilling operation. The hammer motor is a conventional power section and drivetrain with the patent pending hammer mechanism fitted in place of the lower bearing. This assembly has the same geometry of a bent housing motor with all of its capability plus the impact of a rotary hammer. A series of field trials in China have recently been performed to validate the performance increases created by the hammer motor. These trials demonstrated significant cost savings, improved drilling performance, and simplicity of operation.
The challenges involved in maintaining a truly vertical wellbore in the vertical section result in significant losses in drilling efficiency, raising the cost to reach the final target. The increasing complexity of modern drilling programs frequently require extended lateral and horizontal sections to be drilled to allow for production through multiple pay zones. As the reach of these wells is extended further each year, the importance of maintaining a truly straight and vertical top section becomes more critical, but modern solutions to this challenge are either inefficient or prohibitively expensive. A more financially viable solution must be provided for the drilling industry to continue the pursuit of hydrocarbons in these applications.Ensuring that the vertical section of the well is as straight and true as possible is vital in today's drilling operations. This will reduce the frictional forces as much as possible, allowing the driller to more effectively provide Weight on the Bit (WOB) to penetrate the formation. Natural variations in the earth, such as tendencies in the formation caused by layers that are deposited at an angle to the surface or random deposits of hard rock, can push the bit off of its true vertical trajectory, which then require corrections to steer the bit and drill string back on a true vertical course. The curves or kinks created by correcting the drift of the bit create additional points of contact with the wellbore wall by increasing the tortuosity of the vertical section.Unfortunately, the solutions to maintaining true verticality and a straight bore are limited. Controlled drilling is slow and limited in terms of performance, while bent housing motors can correct deviation, but result in increased tortuosity. Rotary Steerable Systems (RSS) offer excellent performance, but are expensive to run both in terms of daily cost and the increased risk of Lost in Hole (LIH) charges.The industry has taken a new step in the evolution of this technology by creating a tool that combines the quality and speed of an RSS system with the economics of a bent housing motor solution. By focusing on simple mechanical and electrical design features, this tool has driven down the cost required to supply RSS performance while maintaining the same high standards. By combining the field proven design elements from a number of existing technologies such as motors and Measurements While Drilling and Logging While Drilling equipment, a robust and reliable system has been developed which not only provides drilling correction in vertical sections, but also provides the real time surveys that are required to keep the well on course. This system is fully autonomous providing an economical solution that will deliver a high quality vertical wellbore while reducing the cost per foot of the well.A major independent oil company estimates they would increase adoption of RSS technology from 5% of their wells to 70% if a product could be offered with a 50% reduced cost. This paper will detail a new system that is being used...
Rotary steerable systems (RSS) have become a standard technology in today's drilling industry. With the advent of the RSS, have come new challenges associated with well bore quality, steerability, and vibration mitigation. The need for technology that supports and compliments RSS operations is the next logical step in providing optimized RSS drilling services. While RSS technology allows drilling of extended reach horizontals and challenging well profiles, the systems have their limitations just as mud motors do. The demand for more complex wells has highlighted the need for technologies that can take the advanced capabilities of the rotary steerable system and push it to the next level of performance. A tool that maximizes the effectiveness of an RSS, reduces costs associated with RSS drilling, and improved borehole quality stands to add an entirely new level of value to rotary directional drilling. A novel technology is now available that has been proven to improve lateral stability and increase bit life by as much as 50% while posting gains in ROP as high as 120% over offset data. Dramatically improved borehole quality has resulted in reduction in materials required for cementing by as much as 25% while reducing the time spent back reaming by 30% and in some cases, alleviating the need for back reaming altogether. Dramatically improved borehole quality in point-the-bit RSS applications. By providing a tighter gauged hole, the severity of downhole vibration and backward whirl were greatly reduced.This paper provides supporting documentation that a technology proven to improve lateral stability while mitigating damaging downhole vibrations is assisting a major operator in maximizing the performance of their RSS operations and allowing operators a new level of performance and cost savings.
Through the years, significant advancements have been achieved with respect to well design, depths drilled, and overall drilling efficiencies. However, in spite of all of these advancements, one major consistent challenge facing the drilling community is the prevalence of downhole vibrations, with specific emphasis on lateral vibrations and shocks.These lateral shocks can be attributed to numerous drilling environmental challenges, and with the exponential increase in long reach laterals, well profiles, and formation changes, the increase in potential for significant shocks to cause damage to key bottom hole assembly (BHA) components is increased as well. To mitigate potential BHA damage, increase ROP, and provide a significant increase in bit life, a novel technology has been developed to tackle these challenges.This vibration dissipation and mitigation tool has proven performance in both land and offshore applications, providing marked improvements over previous conventional solutions. When using this technology in the Gulf of Mexico, ROP improvements yielding an excess of 50% as well as a substantial stick slip reduction were observed, ultimately reducing time drilled and overall drilling costs.The application of this innovative vibration mitigation and reduction technology is unique, especially in comparison to conventional solutions seeking to reduce vibration. Rather than seeking to simply absorb vibrations caused by drill string dynamics as with conventional solutions, this technology seeks to actively change the dynamics of the drill string to prevent these vibrations from ever occurring while offering a system for dissipating the residual vibrations. As this paper will demonstrate, this new technology has proven to successfully provide more control to the driller in applications once thought to be without a solution to such vibrational challenges. This paper will discuss the advantages of this formative technology along with providing case history and accompanying supporting run data to quantify the performance of this innovative technology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.