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Collaborating Authors
Jain, Rachna
Rapid Crosslinking Polymer Provides an Additional Blowout-Preventer Barrier
Nedwed, Tim (ExxonMobil Upstream Research Company) | Kulkarni, Kaustubh (ExxonMobil Upstream Research Company) | Jain, Rachna (ExxonMobil Upstream Research Company) | Mitchell, Doug (ExxonMobil Upstream Research Company) | Meeks, Bill (ExxonMobil Development Company) | Allen, Daryl P. (Materia) | Edgecombe, Brian (Materia) | Cruce, Christopher J. (Materia)
Summary The industry maintains well control through proper well design and appropriate controls and barriers. This has made a hydrocarbon release from loss of well control a very–low–probability event. The current final barrier to maintain control is a valve system [blowout preventer (BOP)] located on top of wells, capable of isolating them by sealing around or shearing through obstructions that might be in the well (e.g., drillpipe and casing). Although the risk is low, there are still concerns regarding well control, especially for operations in sensitive environments. Adding an additional barrier could alleviate these concerns. We are currently evaluating a concept to respond to BOP seal failure by injecting a liquid monomer and a catalyst below a BOP leak point to rapidly form a polymer–plug seal. Mixtures of dicyclopentadiene (DCPD) and other monomers mixed with a ruthenium–based catalyst cause a rapid polymerization reaction that forms a stable solid. These reactions can occur under extreme temperatures and pressures and can withstand significant contamination from other fluids and solids. Laboratory studies showed that DCPD–based polymer plugs can withstand axial stress of 100 MPa (15,000 psi) without significant deformation, even at temperatures of 200°C and with 20 wt% synthetic–based–drilling–fluid contamination. Viscosity testing performed at 4°C showed that the liquid monomers and catalyst used to form polymers have viscosities low enough to allow rapid injection into a leaking BOP. Polymerization–reaction rates were not affected by the presence of high levels of drilling–fluid contamination or varying reaction temperatures. In all cases, reactions were rapid (less than 45 seconds) and resulted in the formation of solid polymers.
Advanced Well Control using Rapid Cross-linking Polymers
Nedwed, Tim (ExxonMobil Upstream Research Company) | Kulkarni, Kaustubh (ExxonMobil Upstream Research Company) | Jain, Rachna (ExxonMobil Upstream Research Company) | Mitchell, Doug (ExxonMobil Upstream Research Company) | Meeks, Bill (ExxonMobil Development Company) | Allen, Daryl P. (Materia Inc.) | Edgecombe, Brian (Materia Inc.) | Christopher, J. Cruce (Materia Inc.)
Abstract Industry maintains well control through proper well design and appropriate controls and barriers. This has made loss of well control a very low probability event. Currently the final barrier to maintain control is a valve system (blowout preventer or BOP) located on top of wells capable of sealing around or shearing through obstructions that might be in the well (e.g. drilling pipe and casing) to isolate the well. Although the risk is low when proper drilling practices and design are employed, there are still concerns about well control especially for operations in sensitive environments. Adding an additional barrier could alleviate these concerns. One scenario for well control loss is if the BOP fails to seal allowing drilling fluids and reservoir fluids to flow. We are currently evaluating a concept to respond to such an event and seal leaking BOPs by injecting a liquid monomer and a catalyst below a BOP leak point to form a polymer-plug seal. Mixtures of dicyclopentadiene (DCPD) and other monomers mixed with a ruthenium-based catalyst cause a rapid polymerization reaction that forms a stable solid. These reactions can occur under extreme temperatures and pressures and withstand significant contamination from other fluids and solids. Lab studies have shown that DCPD-based polymer plugs can withstand axial stress of 15,000 psi without significant deformation even at temperatures of 200°C and with 20% drilling fluid contamination. For well control, one option is to preposition monomer mixes and catalyst into pressurized cannisters located at or near subsea BOPs while drilling high-complexity wells. Connecting the pressurized cannisters to appropriate ports on the BOP will allow rapid transfer. During a well-control event, actuating valves would rapidly force the monomer mixes and catalyst from the cannisters into the BOP to initiate polymerization. Polymerization reactions can be as short as a few seconds depending on the monomer mix and catalyst. The resulting solid polymer plug will block the leak path to potentially seal the well. This paper describes the concept details and summarizes the current status of research.
- Well Drilling > Pressure Management > Well control (1.00)
- Well Drilling > Drilling Fluids and Materials (1.00)
- Well Drilling > Drilling Equipment (1.00)
Experimental Investigation of Pressure-Drop/Flow-Rate Relationship for Small-Aperture Holes for High-Viscosity Fluids
Jain, Rachna (ExxonMobil Upstream Research Company) | Long, Ted A. (ExxonMobil Upstream Research Company) | Dickson, Jasper (ExxonMobil Upstream Research Company) | Brown, Scott V. (Intertek) | Shtepani, Edmond (Intertek)
Summary This paper studies the effect of viscosity and fines-particle loading on the pressure drop across a 4-mm orifice in a specific geometry built to mimic a representative well completion. It also provides experimental data in the range of operating conditions (high aspect ratio, low Reynolds number) that were not covered by any previous studies. The past experiments concentrated on studying the orifices with high aspect ratio (>1) and high Reynolds number (>1,000) or with a combination of low aspect ratio and low Reynolds number. In previous research conducted within the petroleum industry, most of these orifices were validated experimentally for viscosities up to 200 cp only for such completions. The current study focused on a wider viscosity variation (1 to 3,000 cp) with lower flow rates (0.5 to 30 m/d). Even though fines are an integral part of the flow stream passing through the orifice for a sand reservoir, none of these studies further considered the effect of small particles on the orifice performance. The pressure drop was measured across the orifice and through the entire pipe assembly. The measured data were nondimensionalized by use of the Euler number and plotted against the Reynolds number for all rates and viscosities. The data were also compared and validated against commercially available computational-fluid-dynamics (CFD) software. The effect of sand-particle loading was also studied, and its effect on apparent viscosity increase was measured in the laboratory. The pressure-drop/flow-rate relationship and flow coefficient disclosed in this paper can be used to design effective completions for intermediate- to high-viscosity-oil applications and will be able to predict the completion pressure drop more accurately.
Experimental investigation of Pressure Drop/Flow Rate Relationship for Small Aperture Holes for High Viscosity Fluids
Jain, Rachna (ExxonMobil Upstream Company) | Long, Ted A. (ExxonMobil Upstream Research Company) | Dickson, Jasper (ExxonMobil Upstream Research Company) | Brown, Scott V. (Intertek) | Shtepani, Edmond (Intertek)
Abstract This paper studies the effect of viscosity and fines particle loading on the pressure drop across a 4mm orifice in a specific geometry built to mimic a representative well completion. In previous studies, most of these orifices have been validated experimentally for viscosities up to 200cp only for such completions. The current study focused on a wider viscosity variation (1cp – 3000cp) with lower flow rates (0.1m/day - 30m/day). The pressure drop was measured across the orifice and through the entire pipe assembly. The measured data was non-dimensionalized using the Euler number and plotted against the Reynolds number for all the rates and viscosities. The orifice pressure drop data overall agreed well with the limited data that was available from the literature. It was also compared and validated against commercially available CFD software. The effect of sand particle loading was also studied and its effect on apparent viscosity increase was measured in the laboratory. The pressure drop-flow rate relationship disclosed in this paper can be used to design effective completions for intermediate/high viscosity oil applications and will be able to predict the completions pressure drop more accurately.