Badanie charakterystyk hydromechanicznych otworowej pompy strumieniowej

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.

The development trends of hydraulic jet pumps used for the oil-fields exploitation are analyzed. The ambitionto optimize the process of mixing flows has led to the emergence of numerous designs of jet pumps, in which swirling flows are used instead of direct flows. The creation of circulation flows in the pump wet end promotes alignment of coaxial flows velocities, intensifies the process of energies exchange in the liquid, and increases the efficiency of the mixing process. The combination of direct and circulation flows gives a possibility to improve the technical characteristics of jet pumps up to 30%. The dimensions and the mutual orientation of the elements of the pump wet end have a decisive influence on the energy efficiency of the ejection technologies implementation. The optimization of dimensions and orientation of the components of the jet pump necessitates multifactorial experimental studies, which, in addition to the design factors, should also take into account the working mode of the ejection system in the well. The task of optimizing the design and mode parameters of a well ejection system can be solved by simulating the work process of the jet pump using modern software complexes Solid Works and ANSYS, which provide the necessary accuracy of the calculation operations. The efficiency of the ejection system also depends on the depth of its location in the well. Determining the optimum depth of installation of the ejection system in the well presupposes the use of iterative calculation methods with the aid of appropriate computer programmes (for example, Matchad). The development of the hydro-jet operation of oil wells is characterized by the tendency of a joint arrangement of the ejection system and traditional types of downhole pumping equipment. In the design of the combined oil-producing system the jet pump creates a low pressure zone in the bottom and intensifies the inflow ofhydrocarbons from the production horizon, while the traditional downhole pump transports them to the surface. The presence of an additional (jet) pump in the well optimizes the conditions of the main pump use. It improves the energy characteristics of the bottom-hole assembly and increases the efficiency of oil production. The analysis of the hybrid ejection technologies application indicates the prospects of this trend of oil and gas equipment.

The scope of downhole ejection systems is limited by the low value of the efficiency of the jet pump, the value of which usually does not exceed 35 %. Significant energy losses when mixing flows are the reason for the low efficiency of the jet pump. The energy performance of the downhole ejection system can be increased by creating swirling vortex circulating currents in the flow part of the jet pump. This optimizes the nature of the flow mixing and increases the energy performance of the jet pump. In the process of studying the structures, features of the working process and usage experience of ejection systems designed for drilling, operation and repair of oil and gas wells, it is established that the twisting of the working medium in downhole jet pumps can be carried out using guide elements placed at a certain angle in the oncoming flow and rotation of individual parts of the ejection system by means of an external drive and hydraulic turbines. The use of guide elements and hydraulic turbines necessitates the use of part of the energy of the working flow, which drives the downhole jet pump, to spin the working medium. In oil and gas ejection systems, the twisting of working, injected and mixed streams can be realized, as well as the combined simultaneous twisting of several streams. In the process of analyzing the experience of using vortex jet devices, it has been found that the flow twist allows to increase the injection coefficient of the jet pump by 38.1 %, efficiency – up to 70 %, vacuum in the receiving ch amber – up to 40 %. The increase in the basic geometric pa-rameter of the jet pump reduces the effect of flow twist on the characteristics of the ejection system. Flow twisting in downhole jet pumps can be recommended in the implementation of long-term processes, for example, in the ex-traction of formation fluid, when the value of the efficiency of the ejection system significantly affects the cost of oil production.

Permanent monitoring and remote control of the operation mode of the hydraulic jet pump allows increasing the efficiency of the hydrajet mode of oil wells operation. Based on the analysis of the workflow of the ejection system, the authors reveal the relation between the density and flow rate of the mixed flow and the operating parameters of the oil hydraulic jet pump in the form of nonlinear dependencies, which make it possible to carry out remote control over the flow rate in the bottomhole circulation circuit. In the process of modeling the hydraulic relations between the elements of the ejection system, a binary diagram is constructed. This binary diagram is created in the form of two combined quadrants and presents the obtained regularities between the parameters of the mixed flow at the well outlet and the operation mode of the jet pump. The authors present the method of remote control over the operation mode of a well ejection system by means of varying the flow-rate of power fluid directed to the well by a ground pump unit and by means of changing the dimensions of the components of the flowing part of the jet pump. The regulation of the operation mode of the hydraulic jet pump occurs by changing the position of the operating point of the pumping unit. In the process of regulating the operation mode of the jet pump by changing the operating flow rate, the authors obtain a series of characteristics of the hydraulic system which determine the coordinates of the operating point of the pumping unit. Adjusting the operation mode of the ejection system by changing the dimensions of the components of the flowing part of the jet pump involves creating a series of its own characteristics with constant characteristics of its hydraulic system. The replacement of the components of the flowing part of the jet pump is carried out in a hydraulic way and does not require round-trip operations in the well. The authors present the graphical interpretation of the proposed methods of regulating the operation mode of the well ejection system in the form of combined characteristics of the jet pump and its hydraulic system built in the single system of coordinates.

A new model is proposed to predict the performance of hydraulic jet pumps, HJP, when pumping two-phase gas-liquid mixtures. The model performance is compared with Petrie et al. (World Oil, Nov. 83) and Jiao et al.'s (SPEPE, Nov. 90) model, using as input data the set of measurements taken by Jiao (1988) when experiencing an industrial HJP. The present model results from the application of the one dimensional conservation law of mass, momentum and energy to the gas-liquid flow throughout the HJP. It differs from the previous published ones because it takes into account the flow of the two-phase compressible homogeneous mixture along the different parts of the device. It is not just an adaptation of a model originally developed for single phase flows, as the existent ones. Until now, most models representing the flow of a gas-liquid mixture in a HJP were adapted from models developed for incompressible single phase flows. The gas compressibility, for instance, is fully considered, as in Cunningham's paper (J. Fluids Eng., Sep. 74), when modeling a jet pump driven by a gas. The solution of the proposed model requires the knowledge of two constant energy dissipation factors, for the flow inside the nozzle and throat. Best values for these factors were obtained performing a regression analysis over Jiao's data. The results showed a consistently better agreement with the experimental data than those delivered by the existing models, over the full range of the operational variables. Introduction Hydraulic jet pumping is an artificial lift method to be considered when difficult applications, such as remote sites (including offshore), crooked holes, or heavy oil production, exist. It presents important characteristics such as simplicity, flexibility and easiness of maintenance. The downhole equipment has no moving parts, and can be removed or installed by fluid circulation or wireline. On the other hand, the hydraulic jet pump is a low efficiency device: just a small fraction of the power fluid energy, around 30%, is actually transferred to the suctioned fluids. Fig. 1 shows the main components of a HJP: the nozzle, suction, throat and diffuser sections. Fig. 2 depicts a schematic of the pressure distribution of the mixture flow along the device. Power fluid, at an injection pressure pi, is forced through the nozzle. As the fluid accelerates due to the area reduction, its kinetic energy increases and the pressure reduces. The pressure gradient (pi - ps), established between the nozzle exit section, n, and the pump suction chamber at pressure pi, is the flow driving force. The power and produced fluids enter the throat, where a mixing process occurs and the pressure increases from p1 to ps. When the produced fluid is a gas-liquid mixture, the main characteristics of this process, usually referred to as a mixing shock, are:the momentum transfer from the power to the produced fluid andthe flow regime transition taking place within a short finite length. The mixing shock process apparently determines the energetic efficiency of the pump. In the diffuser, kinetic energy is again converted into pressure. The gas-liquid mixture leaves the diffuser at a pressure pd. There are thousands of jet pumps installed in oil wells, most of them suctioning two-phase gas-liquid mixtures. However, some models developed to predict the pump performance when the produced fluid is a gas-liquid mixture are mere adaptations of single-phase flow models. The gas compressibility effect is not taken into account, and some of the proposed adjustments have no theoretical support. An exception is Alhanati's model, which requires a demanding numerical solution, and it is not suitable for inclusion in computer programs that carry out the overall design of the installation. P. 333

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.

A significant productivity loss occurs when the pressure in an oil reservoir is depleted to the point where the wells no longer flow. Post-pandemic COVID-19, operators worldwide are looking for an increase in production from the existing wells so that the cost of drilling new wells is minimized. Some means of an artificial lift must be adapted to efficiently bring the well fluid to the surface. For this application, a highly viscous crude oil (17.5 API) but inactive well with no natural production was selected as a candidate well and the data from the customer was utilized to construct a Jet Evaluation and Modeling Software (JEMS) model. A reverse circulation jet pump with a 12B combination was installed in the sliding sleeve door (SSD) at a depth of 5,250 ft using a slickline. The production performance was achieved by injecting the power fluid into the annulus via a jet pump to generate the required drawdown and to lift the reservoir fluid through tubing to the surface. The monitoring of the production rate was performed based on the surface pumping parameters. Initially, the injection pressure and injection rates were kept low to gently offload the well. The flow behavior was further optimized at an increased pumping rate where the effect of injection pressure and the flow rate (1,700 psi and 2,350 barrels per day) was adjusted to optimize the production performance. The production enhancement of approximately 1,400 barrels per day (BPD) was noticed when the injection pressure was set at 1,700 psi. The production was routinely monitored in the customer facility for investigating the jet pump performance evaluation and further fine-tuning of surface parameters. The setup was further extended to safely handle 120,000 ppm of Hydrogen Sulfide and would be flared in case of any emergency release. This paper will discuss in detail the operation which generated 1,400 BPD additional production for the operator from a heavy oil well, which was previously inactive, with exceptionally lesser operational costs. This was the first jet pump installation for this operator, and the project's success significantly increased their production and revenue. The pump has been producing for the last thirty six months without any maintenance being done to the pump, which significantly reduces the cost of the operation. The operator considers the application of this technology to be a success and will consider installation in more wells in the future.

A method for optimizing power fluid to a network of jet pump wells is established. Jet pump performance is modeled by numerically solving a system of equations for specific throat and nozzle geometries. An upper boundary is established of the most efficient geometries for each well which creates a continuous function relating power fluid to oil production. Jet pump oil wells are segregated into networks which share a common power fluid surface pump. These boundaries are added together to create a non-linear objective function. To solve power fluid distribution in a network, a reduced Newton method is applied that incorporates active constraints. System constraints are that the total network power fluid is at or below surface pump capacity and that each power fluid rate is non-negative. Upon successful convergence, the power fluid estimate per well is passed to a discrete algorithm to choose between either a high or low power fluid jet pump. A computer program is developed capable of implementing the optimization method. This program is successfully tested on an eight well network, determining whether an additional well can be supported with existing equipment. The continuous optimization is fast, converging in four iterations to an answer. Results from a discrete algorithm are displayed with individual oil well jet pump geometries. Any engineer can run this program, providing the benefit of a unified approach to decision making. This is a significant improvement, since no previous methods have been found in literature on how to distribute power fluid across a jet pump network.

The article proposes a jet pump for the bottom hole assembly. The developed supra-bit jet pump provides an additional circulation loop of the drilling fluid above the bottom of the well, which creates a local depression of the formation. In addition, the jet pump grinds the sludge injected from the annular space in the mixing chamber and feeds it to the bridging machine, which is included in the assembly, for temporary isolation of the productive formation. Isolation of the productive formation is necessary to prevent the flow of formation fluids into the wellbore when underbalanced. Grinding of the sludge in the jet pump is ensured by the cross flows of the working and injected liquid, which occur during the angular and eccentric displacement of the working nozzle of the jet pump relative to the mixing chamber. The angular and eccentric displacements of the working nozzle, the roughness of the flowing part of the mixing chamber and the diffuser, at which the pressure losses in the jet pump are insignificant, have been determined. Recommendations are proposed for increasing the efficiency of the jet pump in case of non-stationary operation at the bottom of the well, which occurs as a result of ground vibrations of a roller cone bit and uneven supply of working fluid by mud pumps.

Insufficient energy performance of ejection equipment and a high probability of non-operating modes of its operation reduce the efficiency of downhole jet pumps. The method of determining the design and operating parameters of the well ejection system, which provide the maximum efficiency of the jet pump, is presented. The proposed algorithm for determining the optimal values of the geometric dimensions of the flowing part of the jet pump involves the construction of a series of pressure characteristics for different values of its geometric parameter, the calculation of the efficiency and the determination of the injection ratio and the relative pressure corresponding to its maximum values. During the studies, the main geometric parameter of the jet pump varied in the range from 2 to 6, given that these geometric dimensions are used in jet devices common in the oil industry. The optimal dimensions of the current part of the jet pump are obtained in the process of studying its pressure characteristics, and the optimal dimensions of the washing system of the bit - in the process of studying the characteristics of the hydraulic system. The design of an at-bit ejection system, which allows to increase the mechanical drilling speed, the passage of the bit, to stabilize the moment on the bit, to reduce its level of vibration and to control the antiaircraft angles of the well is considered. The efficiency of using at-bit jet pumps is in the following: an increase in the mechanical drilling speed up to 18.7%, the passage of the bit up to 50.8%. The research established the optimal diameters of the working nozzle, mixing chamber and bit nozzles, the distance between the working nozzle and the mixing chamber, the injection ratio and the relative pressure of the at-bit jet pump. The obtained values ​​of design and mode parameters exclude the occurrence of cavitation modes of operation of the ejection system and allow the operation of jet pumps with maximum efficiency.

This paper presents the performance and compatibility of using jet pumps with hydraulic pumping bottom-hole assemblies that were designed to work with hydraulic piston pumps in an attempt to reactivate idle wells in a heavy oil reservoir, offshore South-West Trinidad. The resilience of the already installed hydraulic bottom-hole assemblies made it easier to select jet pump as the artificial lift method for reactivation. Jet pumps were designed with dimensions to fit in the hydraulic bottom-hole assemblies. Assemblies were modified by using a 13 ft length of 2" pipe inside them to ensure that the seals in the pumps and the polished sections of the assemblies meet at the same depth. The production string from the triple string completion was isolated since only 2 completion strings were required for operation, leaving the power oil injection and fluid return strings active. Jet pumps were installed on 4 wells. Performance was monitored using sonologs to determine fluid levels and clamp-on ultrasonic flowmeters to determine injection and production rates. Results showed that drawdown was occurring and production was obtained from all 4 wells during the first 4 months of operation since submergences were lower than the static levels. After this period, the submergences of 3 wells increased to the static levels and test rates showed that these wells were not producing. The submergence of the 4th well was fluctuating and tested 76 bpd. On inspection, it was discovered that the throats and nozzles of the other 3 wells were plugged with seal fragments from the surface power oil pumps. The jet pumps were cleaned and reinstalled after which the submergences dropped drastically within the first month of returning to operation. From these results, it can be concluded that the jet pumps are compatible with the modified hydraulic pumping bottom-hole assemblies. All 4 idle wells completed in this heavy oil reservoir were successfully reactivated however the performance was affected by plugged nozzles and throats of the jet pumps by seal fragments from the surface power oil pumps. Submergences could be reduced to optimize all 4 wells by changing the nozzle and throat sizes to achieve optimum performance and production rates with the maximum power oil injection pressure of 2400 psi. This paper describes the experience of using jet pumps in the East Soldado field to reactivate heavy oil wells by making minor modifications to the existing hydraulic bottom-hole completion that was designed to be used with hydraulic piston pumps. The use of jet pumps was motivated by the need to reduce workover and operating costs together with the demand to increase oil production. This modification was successful based on the production and monitoring parameters obtained.

We set out to improve the existing design of a polycrystalline diamond bit with a steel or matrix body with the purpose of creating a hydro-monitoring effect. The research object was the hydraulic system of a diamond bit with a near-bit jet pump. The near-bit ejector system was studied by a theoretical analysis of the operation of the bit hydraulic system by means of canonical dependencies and hypotheses. A hydraulic system for a polycrystalline diamond bit is proposed. This system includes a high-pressure jet pump, which enhances the hydro-monitoring effect at the bottomhole. The main hydraulic characteristics of the bit flushing system with a jet pump are as follows: at a drilling pump feed of 18.4 l/s and a drilling fluid density of 1180 kg/m3, the working coefficient of jet pump injection equals 0.34; the working nozzle diameter equals 10.3 mm; the mixing chamber is 11.9 mm, bit hydromonitor nozzles are 11.1 mm; the number of hydromonitor nozzles is 3; the velocity at the exit of hydromonitor nozzles is 85.0 m/s; the pressure drop at the bit is 15.7 MPa. The possibility of using the hydro-monitoring effect enhanced by a near-bit jet pump was substantiated, since the velocity at the exit from the hydro-monitoring nozzles is sufficient to destroy most rocks (sandstone, limestone, dolomites, rock salt, gypsum stone, basalt, marble, granite). The jet pump in the proposed design of a polycrystalline diamond bit creates an additional circulation circuit above the bottomhole, injects cuttings from the annular space and feeds them to the hydro-monitor nozzles. This enables a more efficient destruction of the bottomhole rock. The power of hydro-monitor jets is sufficient to improve drilling performance.

This paper describes the development and field testing of a wireline-retrievable, subsurface safety valve tailored for jet pump production systems. An examination of earlier safety system components adapted to hydraulic pump enhanced production systems is provided to show the evolution of design features involved in this new valve. From conceptual design stages to the actual field implementation and operation, a versatile pump power fluid-operated safety valve specifically designed for jet pumps is presented.

The relevance of the study is determined by the ability of borehole jet pumps to increase the efficiency of technological processes in difficult mountainous and geological conditions. The aim was to establish the laws of transformation of the velocity profile in the production inlet chamber of a borehole jet pump based on the construction and subsequent analysis of the distribution of kinematic parameters of the total working and injected flows. Simulation of the operating process of the ejection system was performed in the ANSYS software and calculation module for four three-dimensional models of a borehole jet pump. The geometric models are constructed with an uneven density of calculation elements in places of complex geometry and a high gradient of hydrodynamic parameters. For each of the studied models, a series of velocity profiles placed at regular intervals at different distances from the pump throat section of the production inlet chamber was constructed. The constructed velocity profiles include sections with uniform and nonlinear distribution of kinematic parameters of mixed flows. It is established that the maximum values of the velocity of mixed flows are present on the axis of the jet pump and are the same for all the studied models. The axial velocity of the mixed flows decreases as the distance to the pump throat section of the production inlet chamber increases. The minimum axial velocity was obtained for a jet pump model with a maximum production inlet chamber length. For two models of a jet pump with a production inlet chamber length of 287 mm and 328 mm, stabilisation of the axial velocity values of the total working and injected flows was obtained. The immutability of kinematic parameters for these jet pump models indicates the completion of the process of equalising the velocities of mixed flows. Taking into account that if the required dimensions of the kinematic stabilisation section are exceeded, hydraulic losses in the flow part of the ejection system increase, its optimal design corresponds to a model with a jet pump production inlet chamber length of 287 mm. The practical value of the study lies in the fact that this design provides the maximum efficiency of a borehole jet pump

The reliable calculation of tubing pressure drops in oil and gas wells is important for the most cost effective design of well completions. None of the traditional multiphase flow correlations works well across the full range of conditions encountered in oil and gas fields. Consequently, two of the recently published "mechanistic" models, one by Ansari, the other by Hasan & Kabir, were evaluated. The performance of these methods was compared against traditional correlations in three ways: The predicted against measured pressure drops were compared for stable flow conditions using 246 data sets collected from 8 producing fields, including a gas and gas-condensate field. None of these data were available to the developers of any of the multiphase flow models evaluated. Suitable methods should reliably predict the "lift curve minima". This determines when a well may need to be "kicked off', artificially lifted or recompleted. The multiphase flow model must not contain discontinuities or be subject to convergence problems. No single traditional correlation method gives good results in both oil and gas wells. In fact, most of the traditional methods which work reasonably in oil wells give very poor predictions for gas wells. Hasan & Kabir's mechanistic method was generally found to be no better than the traditional correlation methods. However, the Ansari mechanistic model gave consistently reasonable performance. Although it did not give the most accurate results in every field, it gave reasonable results across the complete range of fields studied. The Ansari method also gives a reliable prediction of the lift curve minima. Areas in which it needs improvement were identified. By comparison the best of the traditional methods, the Hagedorn & Brown correlation, gave good results for stable flow conditions in oil wells, but it does not correctly predict the lift curve minima. A field example shows how this can lead to erroneous conclusions.