Parameter substantiation of supra bit jet pump for productive formation opening

The purpose of the study is to develop a supra bit jet pump taking into account the unsteadiness of low-speed drilling for crushing the cuttings injected from the annular space under productive formation opening. The article proposes a device for drill string bottom assembly intended for the initial opening of the productive formation. The device includes a supra bit jet pump and a colmatator. The jet pump creates an additional circulation loop of the drilling fluid above the well bottom, crushes the cuttings injected from the annular space in the mixing chamber and delivers it to the colmatator. An additional circulation loop above the well bottom creates a local drawdown of the formation while maintaining the hydrostatic pressure in the well. Crushing of cuttings in the mixing chamber of the jet pump occurs due to the creation of cross flows in the jet pump. The cross flows are provided due to the angular and eccentric displacement of the working nozzle of the jet pump relative to the mixing chamber. The colmatator creates an impermeable screen on the borehole wall for temporary isolation of the productive formation under initial opening. The conducted study allowed the authors to propose head characteristics of the jet pump taking into account the angular, eccentric displacement of the working nozzle. The head characteristic of the jet pump has been developed for the unsteady operation of the jet pump in the drill string bottom assembly. The head characteristics take into account the roughness of the flow path of the jet pump. Using the head characteristics, the permissible displacements of the working nozzle of the jet pump have been determined. Recommendations for the design of jet pumps for drill string bottom assemblies are proposed.

Strategy of Compatible Use of Jet and Plunger Pump with Chrome Parts in Oil Well

During oil fields operation, gas is extracted along with oil. In this article it is suggested to use jet pumps for utilization of the associated oil gas, burning of which causes environmental degradation and poses a potential threat to the human body. In order to determine the possibility of simultaneous application of a sucker-rod pump, which is driven by a rocking machine, and a jet pump (ejector) in the oil well, it is necessary to estimate the distribution of pressure along the borehole from the bottomhole to the mouth for two cases: when the well is operated only be the sucker-rod pump and while additional installation of the oil-gas jet pump above its dynamic level. For this purpose, commonly known methods of Poettman-Carpenter and Baksendel were used. In addition, the equations of high-pressure and low-pressure oil-gas jet pumps were obtained for the case, when the working stream of the jet pump is a gas-oil production mixture and the injected stream is a gas from the annulus of the well. The values which are included in the resulting equations are interrelated and can only be found in a certain sequence. Therefore, a special methodology has been developed for the practical usage of these equations in order to calculate the working parameters of a jet pump based on the given independent working parameters of the oil well. Using this methodology, which was implemented in computer programs, many operating parameters were calculated both for the well and for the jet pump itself (pressures, densities of working, injected and mixed flows, flow velocities and other parameters in control sections). According to the results of calculations, graphs were built that indicate a number of regularities during the oil well operation with such a jet pump. The main result of the performed research is a recommendation list on the choice of the oil-gas jet pump location inside the selected oil well and generalization of the principles for choosing the perfect location of such ejectors for other wells. The novelty of the proposed study lays in a systematic approach to rod pump and our patented ejector pump operation in the oil and chrome plating of pump parts. The result of scientific research is a sound method of determining the rational location of the ejector in the oil well and the calculation of its geometry, which will provide a complete selection of petroleum gas released into the annulus of the oil well. To ensure reliable operation of jet and plunger pumps in oil wells, it is proposed to use reinforcement of parts (bushings, plungers, rods, etc.) by electrochemical chromium plating in a flowing electrolyte. This has significantly increased the wear resistance and corrosion resistance of the operational surfaces of these parts and, accordingly, the service life of the pumps. Such measures will contribute to oil production intensification from wells and improve the environmental condition of oil fields.

Assessment of Cavitation Erosion in a Water-Jet Pump Based on the Erosive Power Method

Cavitation affects the performance of water-jet pumps. Cavitation erosion will appear on the surface of the blade under long-duration cavitation conditions. The cavitation evolution under specific working conditions was simulated and analyzed. The erosive power method based on the theory of macroscopic cavitation was used to predict cavitation erosion. The result shows that the head of the water-jet pump calculated using the DCM-SST turbulence model is 12.48 m. The simulation error of the rated head is 3.8%. The cavitation structure of tip leakage vortex was better captured. With the decrease of the net positive suction head, the position where the severe cavitation appears in the impeller domain gradually moves from the tip to the root. The erosion region obtained by the cavitation simulation based on the erosive power method is similar to the practical erosion profile in engineering. As the net positive suction head decreases, the erodible area becomes larger, and the erosion intensity increases.

Multiphase Flow Boosting Without Using a Mechanical Multiphase Pump – Use of Innovative Surface Mounted Technology for Boosting Production from Inactive Multiphase Wells

Depleting reservoir pressures of mature fields or wells backing out due to high production line pressures can cause severe restriction in production from many oil wells, eventually leading to a complete cessation of production. These wells, however, still have considerable hydrocarbon reserves that can be recovered. Conventional methods to bring such marginal or inactive wells back into production involve power hungry multi-phase pumps or well intervention techniques such as N2 injection, workover, redrilling and artificial lift systems. Such methods are highly expensive and may require substantial infrastructure, especially on offshore satellite platforms which have limited facilities and space. Multi-Phase Surface Jet Pumps (MPSJPs), innovatively combined with novel compact separation, provide a surface mounted, compact, maintenance free and simpler method for boosting production from inactive multi-phase wells, without consuming any electrical power or fuel gas and avoiding any well intervention. Multi-Phase Surface Jet Pumps (MPSJPs) are passive devices which use the energy of existing high pressure single/multi-phase fluids to reduce the Flowing Wellhead Pressure (FWHP) of low pressure multi-phase wells and boost their pressure to the downstream production header pressure. This patented system involves the use of a compact in-line separator upstream of the MPSJP to separate the gas & liquid phases and use the predominant liquid phase as the high-pressure motive fluid. MPSJPs can be used on their own or in combination with other boosting systems (e.g. ESPs, gas lift etc.). The applications also include revival of watered out, idle oil and gas wells. Results from multiple worldwide applications have shown that MPSJPs can successfully boost production from low producers as well as revive dead wells that have not been flowing for a period of time. Wellhead pressures have been considerably reduced and production increases have ranged from 20% to 40% per well. The advantages that MPSJPs offer over conventional technologies such as Multi-phase pumps, ESPs and well intervention techniques are several. MPSJPs are surface mounted (so well intervention is not required), comparatively low cost, have no moving parts, consume zero fuel gas/electrical power, have low footprint and use already available fluid energy. They are tolerant to variations in flow conditions, gas volume fractions (GVF) and associated slugging. They reduce the CO2 footprint by not consuming power and provide a radical, innovative, economical and environmentally friendly alternative to conventional methods. This paper discusses the use of MPSJPs and cites various case studies. The design and operational criteria are also highlighted.

Cross Flow Analysis over the Jet Pumps of a BWR-5 Reactor

The recirculation system of a BWR-5 has 20 jet pumps. They are submerged in water in the cylindrical annular zone of the reactor. Their main function is the development of a forcing flow through the nuclear core. It increases the power of the reactor compared with the one obtained by natural circulation. These components have an important safety function in the operation of the reactor. In accordance with document BWRVIP-41 R4, it was concluded that the vibration induced by cross flow over the jet pump assemblies is one of the degradation mechanisms of such pumps. In this paper, the vibration induced by the cross flow at a jet pump assembly BWR-5 was analyzed. A numerical approach was developed. The natural frequencies were obtained, considering the Fluid-Structure Interaction (FSI). The first natural frequency was 25.7 Hz. A Computational Fluid Dynamics (CFD) analysis was carried, in conjunction with the Power Spectral Density (PSD). A frequency of vortex generation of 0.48 Hz was obtained. A vortex generation analysis was carried out with the Q-criteria. The results showed that resonance conditions are unlikely. Therefore, the structural integrity of the jet pump assemblies is maintained.

Overcoming Extreme Technical and Logistical Challenges to Successfully Cleanout 76,000-LBM Proppant

A fracture treatment in offshore Tunisia screened out leaving over 76,000-lbm proppant in the wellbore. The well was significantly under-hydrostatic. The platform was small and had limited deck space and low capacity cranes. The completion incorporated chrome tubulars with a history of causing abrasion failure to coiled tubing strings. The challenge was to efficiently and safely clean out the proppant with coiled tubing (CT). A prior cleanout campaign had been conducted with concentric CT and jet pumps. An initial design focused on repeating this method. The engineering analysis had to account for fluid and nitrogen pumping being conducted from a supply vessel, limited nitrogen volume, low the solids return rate due to surface handling limitations, and no fluid discharge permitted to sea. A combined engineering, logistical study, laboratory testing and risk assessment was undertaken over the course of three months. Engineering utilized advanced cleanout modelling software to review concentric CT cleaning, forward cleaning (with and without optimizing cleaning Bottom Hole Assembly (BHA) and with various sizes of CT), and reverse circulating. Logistics analyzed the overall operation time, fluid and nitrogen requirements and the number of boat trips to replenish/change well returns and nitrogen. Three additional challenges were present. First, proppant could have packed off creating difficulties for some of the processes under review. Laboratory testing was conducted and confirmed this would not be a concern. Second, the well was sour and considerations for protecting the CT string and handling hydrogen sulfide (H2S) in the return stream were required. Third, CT string optimization was required to reduce potential abrasion failures. Avoiding CT failure was paramount as the string would be boat spooled onto the platform and any failure would severely impact operating time and project finances. The chosen method was primarily fluid only reverse circulating when cleaning above the formation, changing to forward circulated two phase operation when close to the formation. The downhole pressure gauge in the completion provided early warning of lost returns or of gas kicks. The operation was successfully, efficiently and safely completed in August 2019. The well was handed back to production 8 days ahead of schedule. The paper will cover the complete concept and detail design, execution and post-job analysis.

Flow fields of a non-Newtonian fluid in vortex chamber pumps

Problem. Pumping different fluids by hydraulic transport is associated with fast wear of the pump contact surfaces. The fluids being pumped are often non-Newtonian. The use of jet pumps for pumping is impractical due to low efficiency. Vortex chamber pumps may have higher efficiency when pumping non-Newtonian fluids, however, their operation on such fluids has not yet been studied. The aim of this work is to study the characteristics of the flow fields of a non-Newtonian fluid using the example of a Bingham fluid in the vortex chamber pump. Methodology. Predicting pump energy performance and determining flow fields for highly viscous fluids using CFD simulations enables advanced jet pumps to handle non-Newtonian fluids. Results. Modeling was carried out based on the numerical solution of the RANS equations with the SST turbulence model. To ensure the operability of the vortex chamber pump when pumping non-Newtonian fluid, with known rheological parameters of the mixture, it is necessary to select the required supply pressure for the active flow, and also to consider the issue of diluting the liquid with water to reduce the mixture viscosity and achieve the specified values of the pumping energy parameters. Originality. The hypothesis that the vortex chamber supercharger can operate on a hypothetical ideal fluid has been confirmed. In this case, the performance indicators of such a supercharger improve and tend to ideal. With an increase in plastic viscosity, the volumetric flow rate of the pumped fluid decreases, and at high values of the viscosity, an active flow is ejected through the axial channels. Practical value. Researchers can use the theoretical results of this work to design new devices for pumping other Bingham fluids, such as oil paint, resins, varnishes, swamp soils, and many others.

Water flow regulator for irrigation canals

A distinctive feature of the irrigated systems of the Russian Federation is a large area of irrigated areas and a significant length of irrigation canals. With a large area of the irrigated massif on small canals, the use of electricity to regulate the throughput of network hydraulic structures is economically ineffective. Preference is given to means of hydraulic automation of water supply. Regulation of the throughput of a hydraulic structure is based on the laws of fluid flow within it. On irrigation canals in Russia, as in world practice, water-operated gates are widely used. One of the disadvantages of such gates is moving metal parts and sensors, which reduce the operational reliability of structures. A new regulator of throughput is proposed, the action of which is based on the injection effect. Compression of the flow by physical elements was replaced by the circulation of surplus water supply between the outlet section of the water supply structure and the downstream. The regulator is built into the pressure drop between the high and low order channels. Regulating the throughput of the tubular water outlet automatically begins after shutting down one or more sprinklers that take water from the lower order canal. After turning the sprinklers into operation, the regulator automatically restores the original throughput. Using the theory of jet pumps, a new method has been developed for the theoretical determination of the main hydraulic characteristics of the regulator. These include the size of the nozzle and the velocities of the injection and injection streams. The derivation of theoretical dependencies was based on the classical equations of fluid mechanics; the flow within the structure was considered quasi-one-dimensional. The obtained calculated dependencies were verified using numerical and physical modeling. The data of the physical and numerical experiment were in good agreement with the theoretical dependences. Further optimization of the controller can be performed by changing its geometric parameters.

STUDY ON CHARACTERISTICS OF A DOWNHOLE VORTEX JET PUMP

This article analyzes the possibility of increasing the efficiency of using downhole jet pumps by swirling the injected flow. To analyze the peculiarities of the local swirling of injected flow, design and technological parameters in the form of the inclination angle of guiding elements, the diameter of the helical trajectory described by the fluid particles, and the flow rates of the swirling flow are studied. Based on the application of the conservation law of fluid momentum in adjacent jets with a parabolic pressure distribution, equations to determine the pressure characteristic of a jet pump are obtained, taking into account the additional dynamic pressure made by swirling the injected flow. In the process of analyzing the obtained relations, has been set the dependence of the relative pressure growth and the efficiency of the ejection system under the conditions of injected flow swirling on the relative flow rate of a jet pump, and an inversely proportional dependence of the above parameters on its main geometric parameter in the form of the ratio of cross-sectional areas of the mixing chamber and the nozzle.