When producing hydrocarbons from an oil well, managing erosion of both surface and subsurface components caused by solids in the flow stream is critical to maintaining operations integrity in both land and offshore assets. Although component lifetime prediction has advanced in the past few decades, the prediction's accuracy remains a major oil and gas industry challenge. Current computational models only provide an initial erosion rate which is usually assumed constant until equipment failure. However, observed erosional rates vary as a function of time due to the geometrical changes caused by equipment material loss, which result in variations in solid particle impingement velocity [
This paper presents an implementation of an erosion dynamics model in ANSYS FLUENT, a commercial computational fluid dynamics (CFD) software, to capture the progression of transient erosion. The model has the capability to capture the effects of surfaces receding from erosion at each time interval. By dynamically adjusting these surfaces and recalculating the local flow conditions in the area, this method can predict new erosion rates for each time interval and achieve fully coupled geometry-flow-erosion interactions.
This new erosion dynamics model was validated against experimental data from both literature and physical testing, and was determined to have accurately captured the observed erosion trends over time in terms of location and magnitude. The model was then employed to study two real world applications: 1) in evaluating the erosion risk for a high-rate water injector, it predicted the evolution of damage to a coupler designed to connect different diameter pipes, and 2) in analyzing facility piping systems connected to an unconventional well, it predicted the transient erosion trend from proppant flowback, which allowed for pipe geometry optimization to increase in erosional life expectancy.
Bailey, Jeffrey R. (ExxonMobil Upstream Research) | Wang, Lei (ExxonMobil Upstream Research) | Tenny, Matthew (ExxonMobil Upstream Research) | Armstrong, Neil Robert (ExxonMobil Corporation) | Zook, Jason R. (ExxonMobil Development Co.) | Elks, William Curtis (ExxonMobil Development Co.)
Design tools and workflows to mitigate drilling vibrations have been developed, demonstrated, and documented for several field drilling applications. This paper provides two new case studies to illustrate how this vibration mitigation methodology may be applied. Dynamic motions of the bottomhole assembly are known to be highly detrimental to the drilling process, resulting in unplanned trips, reduced rate of penetration, shortened bit and tool life, and MWD failures. The utility of the BHA design tool and the associated workflow will be illustrated in the context of how the methods have worked in conjunction with improved operating practices to achieve better drilling performance.
One case study shows how vibrations modeling can be used while drilling is underway to select a better BHA design, when it has been recognized that vibrations are a key performance limiter. Another case study illustrates how the vibrations modeling may be used to choose a preferred BHA design in advance of drilling a well or hole section. This proactive predrill workflow provides for advance planning and alignment with service providers. Both of these case studies illustrate how the method can be used to hindcast field results to understand performance change from one BHA to the next.
Vibrations mitigation through BHA design modification, operating parameter selection, and follow-up surveillance is proving to be highly cost-effective in the operator's "relentless re-engineering?? process to reduce drilling costs. These technology applications are now being applied on a global scale.
Kline, William E. (ExxonMobil Upstream Research Co.) | Chandler, Karen (Exxon Production Research Co.) | Keller, Stuart Ronald (ExxonMobil Upstream Research Co.) | Ottesen, Steinar (ExxonMobil Upstream Research Co.) | Gupta, Vishwas (ExxonMobil Upstream Research Co.) | Tenny, Matthew (ExxonMobil Upstream Research Co.)
Copyright 2005, International Petroleum Technology Conference This paper was prepared for presentation at the International Petroleum Technology Conference held in Doha, Qatar, 21-23 November 2005. This paper was selected for presentation by an IPTC Programme Committee following review of information contained in an proposal submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the International Petroleum Technology Conference and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the International Petroleum Technology Conference, its officers, or members. Papers presented at IPTC are subject to publication review by Sponsor Society Committees of IPTC.