How do you select the best type of subsea pump or compressor for different applications and conditions?

1 Types of subsea pumps and compressors

Subsea pumps and compressors come in different varieties, each with its own benefits and drawbacks. Centrifugal pumps and compressors use rotating impellers to accelerate and pressurize the fluid, but they are sensitive to changes in density and viscosity, and require complex seals and bearings. Positive displacement pumps and compressors use reciprocating or rotary mechanisms to displace a fixed volume of fluid per cycle, but they are bulky, noisy, and prone to wear. Helico-axial pumps and compressors are a hybrid of centrifugal and positive displacement devices, suitable for a wide range of flow rates and pressure ratios, though expensive and requiring advanced control systems.

2 Factors to consider when selecting a subsea pump or compressor

When selecting a subsea pump or compressor, you need to take into account several factors, such as the fluid properties, operating conditions, installation and maintenance requirements, and environmental impact. The fluid properties, such as density, viscosity, composition, and phase behavior can affect the performance and efficiency of the pump or compressor. Operating conditions such as pressure, temperature, flow rate, and head of the fluid can determine the power and torque of the pump or compressor. Installation and maintenance costs can be impacted by the location, depth, and accessibility of the subsea pump or compressor. Additionally, it's important to ensure that the subsea pump or compressor complies with environmental regulations and standards to minimize emissions, noise, and vibrations that can affect marine life.

3 Examples of subsea pump and compressor applications

Subsea pumps and compressors can be used for various applications in the offshore oil and gas industry, such as artificial lift, gas injection, and gas export. Artificial lift is the process of increasing the pressure and flow of the reservoir fluids to the surface facilities, while gas injection is the process of injecting gas into the reservoir to maintain pressure. Gas export is the process of transporting gas from the offshore fields to onshore terminals or markets. Subsea pumps and compressors can be installed near wellheads or along flowlines, injection wells, or pipelines to enhance production, compress gas before injection, and boost pressure and flow of gas respectively. This reduces the need for topside compression facilities.

4 Benefits of subsea pumps and compressors

Subsea pumps and compressors provide several advantages for the offshore oil and gas industry, such as increased production and recovery rates, reduced topside weight and footprint, extended field life and reach, and improved operational flexibility and reliability. Subsea pumps and compressors can raise the pressure and flow of hydrocarbons from reservoirs to surface facilities, decreasing the need for topside processing and compression equipment. Additionally, they can extend the life and reach of fields by enabling the development of low-pressure, high-water-cut, or marginal reservoirs, or by connecting remote or satellite wells to existing infrastructure. Furthermore, subsea pumps and compressors offer variable speed control, remote monitoring, and self-protection features that improve the performance and availability of the devices.

5 Challenges of subsea pumps and compressors

Subsea pumps and compressors can be a challenge in the offshore oil and gas industry due to their complex design, fabrication, installation, and maintenance requirements. Additionally, these devices face technical risks and uncertainties from the harsh subsea environment and dynamic operating conditions. Finally, subsea pumps and compressors need to adhere to the regulatory and environmental barriers of the host country and industry, which can vary depending on the location, depth, and type of the project. High capital and operational costs associated with these devices, as well as their associated subsea power supply, control, and communication systems also make them a challenge.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?