Electrical Submersible Pump ( ESP ) is non a new innovation to oil production line. In fact, the ESP systems powered by electrical downhole motor have been used for decennaries to raise fluids from oil Fieldss. However, during the broad scope of rough downhole environments, the ESP systems have to confront assorted challenges from production.
ESP has become a critical constituent of universe ‘s oil merchandise lines late. It has been designed more immune to scratch by sand, wide scope of high operating temperature and more gas handling. These progresss make ESP able to be applied in rough environments all over the universe broad. The undermentioned treatment of this paper is based on the specific theoretical account of ESP in utilizing on Jacky good which developed by ITHACA ENERGY.
The theoretical account of ESP in utilizing on Jacky well is 562 series, P110 SXD pump, 120 phases which is made by Baker-Hughes Centrilift. The ESP system includes all the needed constituents to reassign electrical power from Jacky platform to downhole, change over the power into gesture power to force the produced fluids to the surface. The ESP downhole system includes:
The constituents of ESP system can diversely depends on the production demands, the Figure 1.1 shows the basic constituents of Jacky ESP system.
The ESP system downhole constituents are designed and manufactured based on Jacky good informations and production demands. For the Jacky ESP system, the gas centrifuge is non required during the low gas ratio and low bubble point of fluids.
Jacky is a little oil accretion near to the Beatrice Field in the Inner Moray Firth country of the UKCS North Sea. The field is penetrated by two Wellss: the find good 12/21-2. Drilled in 1982 and a 2nd oil-bearing good 12/21c-6 early on the twelvemonth 2007. Well 12/21c-6 is a perpendicular geographic expedition good, drilled by ADIT on behalf of ITHACA ENERGY ( UK ) Ltd. The field has been developed utilizing a usually remote-controlled wellhead platform with good 12/21c-6 being completed with a double ESP system which is made by Baker-Hughes Centrilift, merely before first oil in April 2009. The ESP system was designed to runing under a scope of rough conditions. The ESP system has been successfully operated and monitored remotely from Beatrice Alpha platform. ( ref )
Scale Formation in the Jack ESP
Scaling is the one of most chief issues that can do an ESP failure. Unmanaged graduated table may necessitate an ESP alteration out and/or the demand of scale remotion ( e.g. chemical remotion ) . The cost an ESP alteration out can be every bit high as & A ; lb ; 6M ( rig at & A ; lb ; 200k/day for 14days plus with new ESP/equipments ) . In order to optimize running life of ESP, the grading anticipation in the ESP is required. Unlike other constituents in the production system, due to the utmost operating conditions ( high temperature, force per unit area swings and little spreads in the ESP, etc ) , carbonate scaling hazard in the ESP increases with increased temperature and reduced force per unit area. Once graduated table is built up, it can significantly impact the pump public presentation and even do a pump failure.
Since the profitableness of the Jacky field is to a great extent depends on the development and operation cost. In order to accomplish the biggest net income, one of the cardinal factors to driving the undertaking scheme of Jacky field is to command the operational cost of ESP every bit low as operable. In the Jacky Fieldss covering with the production of rough oil and produced H2O, the run-life of ESP is a cardinal fact for the Jacky undertaking to do benefit.
Like any other oil field, the Jacky field besides produces H2O in the fluids ; the H2O cut of Jacky well is about 32 % boulder clay now, this means the well has non face any grading job during the production. Because the H2O in oil emulsion is stabilised in the ESP at current H2O cut and the produced H2O has non been in touch with ESP moisture surfaces. However, the stableness of H2O in oil emulsion will diminish as H2O cut addition and finally will toss into H2O emulsion. Since so, the ESP will endure grading job.
The interior ESP operating temperature lifting and force per unit area dropping are the cardinal factors to impact the graduated tables drop out from produced H2O. The graduated tables could be deposit on the internal surface of ESP, and since the first bed of nucleation built up in the ESP, the grading will arrange really fast. It is one of the cardinal issues impacting the pump efficiency and public presentation. And the pump public presentation is an of import factor for the production to be profitable. So, therefore a demand to optimise the public presentation of Jacky ESP, the grading anticipation inside the ESP under the operating conditions with produced H2O is required.
Aim and Aims
This chief purpose of this undertaking is to measure the grading hazard in the Jacky ESP.
The aims below were identified to fulfill the purpose of this undertaking.
To reexamine the bing instances and information to understand the Baker-Hughes ESP system, and happen out the power flow of ESP system to gauge the heat transportation public presentation in the ESP system.
To analyze the grading formation demands, and happen out when and where the graduated table signifiers inside the Jacky ESP.
To analyse the informations obtained by the well developer, other co-operated and commissioned companies, in order to gauge the optimized and the worst state of affairss of Jacky ESP.
Report the consequence of this undertaking, and name the farther research could be done in the hereafter.
This undertaking is commissioned to measure the grading hazard in the Jacky ESP, including appraisal of heat transportation public presentation in the ESP, heat effects to scaling inclination and scaling anticipation inside the ESP. This undertaking estimates the ESP system power flow, scaling simulations, and how fast the ESP will be blocked by graduated tables at critical points. The appraisal is based on the obtained informations which from dependable beginnings.
In order to finish the undertaking ‘s aims, the following methodological analysiss have been adopted.
The ESP Review
Review literature on Jacky ESP system and to understand the power flow between the different constituents in the system.
Estimate the factors which can lift up temperatures of insider ESP and fluids by heat transportation and system power loss.
Jacky Water Analysis
Review literature of scale formation to understand the procedure of grading, particularly under the ESP operating conditions.
Analyze the Jacky H2O samples and predict the grading inclination by utilizing the commercially available package, Solmineq.
Collect consequences from the package for analysis and anticipation of the graduated tables.
Predict the Scaling Tendency insider the ESP
Analyzes the information which obtained from the ESP survey and Jacky H2O samples analysis to gauge the grading inclination insider of Jacky ESP under possible operating conditions.
Chapter 2 – The ESP Review
The Electrical Submersible Pumping System
The force per unit area difference between reservoir and surface is caused by the natural energy of the tight fluids stored in the reservoir. If the plunging force of force per unit area difference is great plenty, the fluids will flux to the surface of course. However, during the production, when the downhole force per unit area dropped below the degree sufficient to raise fluids to the surface, the downhole force per unit area must be reinforced by unreal lift.
The electrical submergible pump system is a multiple phases centrifugal pump. It has a minimal demand of intake force per unit area to make full the fluids into the pump before it started. The ESP system can non raise fluids from intake force per unit area to nothing. The centrifugal pump has been designed, engineered and built to manage broad scope of rough production conditions for high lastingness and dependability. Since the ESP can run down to well low force per unit area, it can be considered as an effectual and economical manner to pumping reservoir fluids.
Over the decennaries, the engineerings of ESP have been improved by ESP companies ; the ESP has been designed, engineered and manufactured to run under the high temperature, high viscousness, gassy, scratchy and caustic conditions, meanwhile it can raise more fluids.
The ESP constituents
As has been shown in Figure 1.1, the ESP downhole installations include all the needed constituents to plunging fluids from downhole to come up. Each constituent will be discussed as follow.
The ESP Pump
Jacky ESP system pump is a multi-stage centrifugal pump which converts the rotary motion energy from shaft into velocity/pressure that drives fluids to come up. In order to accomplish the production mark rate ( 12,000bbl/d ) of Jacky good, the class of Jacky ESP system pump is designed as assorted flow type to manage high flow rate. In this sort of pump, the fluids flow though the phases both analogues and perpendicular of the shaft way.
The Pump Components
The ESP pump is built up as following indispensable constituents:
Figure 2.1 The ESP Cutaway
( Beginning )
Impeller and Shaft – As shown in Figure 2.2, the impellers are fixed on the shaft, and the shaft is rotated by electrical motor. As the impellers revolving, Weathervanes are convert centrifugal force to velocity/pressure to impact production fluids.
Figure 2.2 The
( Beginning )
Diffuser – The diffusor directs the tight fluids into the suction oculus of following impeller, and it does non whirl.
Shaft – The pump shaft transportations rotation power from electrical motor to the pump though the seal subdivision.
Pump Stage – A pump phase is assembled by unifying an impeller and a diffusor. Figure 2.3 shows a cutaway of an operating pump phase, an impeller assembled into a diffusor and fluids fluxing tract.
Figure 2.3 The cutaway of pump phase ( impeller and diffusor )
( Beginning )
Intake – The pump consumption ( Figure 2.4 ) is the connexion between the terminal of pump lodging and a rim to fall in the ESP seal subdivision, while provides a tract for productions to flux into the ESP.
Figure 2.4 The pump consumption
( Beginning )
Multi-stage Pump Operation
Figure 2.5 shows a multi-stage centrifugal pump. The ruddy pointers are presented as fluids impacted by the revolving impeller. As the impeller rotates, it converts gesture force into the speed of fluids. The xanthous pointers are presented as fluids directed by diffusor into the following impeller above it and reassign the speed energy into force per unit area to raise fluids from downhole to surface.