Artificial Lift is a process of changing reservoir pressure in oil wells in order to increase the flow of oil (or water) to the surface. As production continues, the natural reservoir pressure declines, as such there is no force to push the oil out. What Artificial Lift does is provide this additional drive by increasing pressure.
Artificial Lift is used in mature fields, as well as in newer fields to make projects economics work. More than 75% of wells worldwide ( around 1million) use Artificial Lift. North America is the largest region for Aritifical Lift application, with more than 50% of the market. This is followed by Europe, Asia Pacific and Latin America.
Effective utilization of Artificial Lift requires a detailed analysis whereby almost each well feature makes a difference. Deviation and lateral profiles, pressure and temperature, gas-to-liquid ratio, facilities footprint and many more. Selecting the optimum lift method involves extensive planning, analysis and scenarios. Each method has its own pros and cons and may not be the best method during the later time of the field, although initially it was the optimum solution. Poor selection may result in high operating costs or deferred production, due to wells not being at its optimum production levels. Frequent pump failures, due to sand and solids, tubing wear and many more, result in unnecessary well work-overs.
When it comes to breaking down the market by type, it is difficult to have a very accurate segmentation, as the numbers are conflicting, sometimes. However, as a guide (95% accuracy) the segmentation of Artificial Lift industry looks like as below. In offshore applications, ESP and Gas Lift significantly dominate the market of Artificial Lift, with smaller proportion of PCP and Jet Pumps
There are two major options to increase pressure:
- A device inside the well that would provide required pressure to lift the fluids. Normally the device is a pump with different operating basics
- Injecting pressurized gas produced from a well, to the production section of the reservoir, through a down-hole valve
Artificial Lift encompasses various technologies as illustrated below.
- Artificial Lift
- Gas Lift
- Intermittent gas lift
- Continuous gas lift
- Pump Assisted
- Plunger Lift
- Beam / Rod Pumps
- Hydraulic jet pumps
- Progressive cavity pumps (PCP)
- Electrical submersible pumps (ESP)
Globally, ESP, Beam / Rod Pumping and Gas Lift are the key technologies used in Artificial Lift and together represent more than 80% of the population. Each of the methods has its own advantages and disadvantages, and production profiles, reservoir nature, costs and a number of other variables, would drive the approach and technical parameters. Below is a summary comparison of each technology that would give general idea of the Artificial Lift systems available.