Methodology
Methods of Artificial Lift\
Beam pumping: It is the most significant type of artificial lift pump system. In this type, equipment is engaged on and below the surface. The beam pumping does maximize force and pushing oil on the surface. It comprises a sucker rod pump and a sucker rod string. The method of Beam pumping is regarded as the most popular jack pumps mainly observed on onshore oil wells. The method of beam pumping rocks backwards and forward. It is further attached to a sequence of rods referred to as the sucker rods. After that, the sucker rods are joined to the sucker rod pump, which is installed as a constituent of string tube. Functioning of the rod string, sucker rod and sucker rod pump are quite similar since the system of beam pumping rocks backwards and forward. The oil is lifted to the surface from the reservoir by the sucker rod pump via well. For the efficient functioning of the beam system, a method to minimize speed has been developed so that the unit of the pump moves uniformly.
Hydraulic pumping: It is another system of artificial lift pumping, which is quite different from the beam pumping system. Application of a downhole hydraulic pump is made rather than sucker rods which perform the function of lifting oil to the surface. In this case, the construction is forced against the pistons so that the adequate pressure is caused and fluids are lifted to the surface. The two pistons are the general constituents of Hydraulic pump that are joined by a rod. Clean oil that has already been lifted from the well is used to power the surface hydraulic pumps and the subsurface hydraulic pumps.
Hydraulic pump
Electric submersible pumping system: A centrifugal pump below the surface of the reservoir fluids has been employed. The pump comprises many blades, which performs the function of moving the fluids in the well. The overall system of electric submersible pump is developed at the bottom of the string tube. An electric cable runs throughout the length of the well, which associates the pump to the surface. Application of artificial lift in case of the electric submersible pump is possible only if the blades are spun on the pump shaft; pressure is put and forced on the surface. It has been noticed that the electric submersible pumps regularly can lift more than 25,000 barrels of fluid.
Gas lift: Gas lift is considered as the most popular technique of artificial lift. Its main function is to inject compressed gas inside the well so that pressure can be reestablished. In situations when a well is, flowing in the absence of an artificial lift, in such cases, a natural form of gas lift is used. By minimizing the level of fluids in the well, the injected gas minimizes the pressure on the bottom of the well. Gas lift is the most favourable selection for offshore applications with only a few surface units. The main function of gas lift is to minimize the fusion of oil, gas and water by maximizing the liquid-gas ratio.
Reservoir pressure and well productivity of an artificial lift system
Future and present pressure of reservoir and well productivity are the most significant elements to be taken into consideration which selecting an appropriate technique of artificial lift. One of the two performance connections of inflow is viewed when the liquid rate is plotted against bottom hole pressure.
Selecting an artificial lift system
The most efficient method of artificial lift must be chosen to gain maximum benefits from the manufacture of gas or oil field. Traditionally, the techniques, which were utilized to choose the lift method for a particular field, is different. The methods comprise:
- Experience of operator
- To determine the lists of pros and cons.
- Techniques which are available for installations in definite areas
- To identify the techniques which will lift at the preferred rates.
- To determine costs based on operating, production capabilities.
The factors, which have to be taken into account while selecting an artificial lift system, are:
- Cost of capital
- Costs based on operating
- Geographical location
- Flexibility in production
- Stability
If an efficient selection of artificial lift system is not made, key factors such as servicing expenses based on the long term delayed production at the time of workovers can lead to a reduction in the net present value of the project. Production of reserves must be made on time along with low rates of operating. Detailed data is necessary for the overall analysis of current values which may not be readily available.
Conclusions
Artificial lift methods perform a significant role during the process of oil field production. Several stakeholders, sectors and companies are dealt with when procedures related to selection, monitoring, installation, evaluation of systems takes place. To increase the life of specified artificial lift system and to increase field production efficiently, proper analysis and understanding of key factors such as the experience of companies, the location of the field are significant. The artificial lift system has remained the most effective method of production in increasing production from gas and oil wells. However, artificial lifting of gas and oil remains a critical matter due to the reduction in pressure of the reservoir. Different methods of artificial lift such as hydraulic pumping, sucker rod pumping, electric submersible pumping, gas lift, progressive cavity pumps have also been analyzed in detail. Progressive cavity pumps have high efficiency of electricity, but they generally lose their efficiency with depth. Whereas, Gas Lift has the capacity to handle a huge volume of solids with minor difficulties. Gas lift faces problems in case of dirty surface lines and is not effective enough to lift small fields. Electric submersible pumping is easy to operate and is readily available in several sizes. High voltages are mandatory in case of electric submersible pumping and have a deficiency in the rate of production. Sucker rod pumps are quite simple to operate and can be maintained easily. The major disadvantage is that difficulty is experienced in drawing fluid below the pressure of bubble point.