Chemical injection pumps

Application

Electrical chemical injection pumps inject chemicals into natural gas pipelines at remote drilling sites to prevent hydrate blockages.

Output requirement	Between 7 and 30 W
Power requirement	170 – 720 Wh/day
Autonomy requirement	At least 4 months without user intervention, especially in winter

The challenge

Ensuring 100 % reliable operation in remote locations, in rough weather and climate conditions, even in extreme cold. Making service intervals as long as possible, reducing fuel costs, minimising environmental pollution by omitting degassing which is needed when pneumatic pumps are used.

More oil and gas applications

SCADA systems
Pipeline safety

Chemical Injection Pump

The Uses and Benefits of a Chemical Injection Pump

There are many logistical and engineering concerns associated with the oil and gas sector. However, safety and efficiency are paramount in these demanding times. Petrochemical firms have therefore developed several measures in order to ensure that nothing is left to chance. Examples include computerised flow regulators, automatic shutoff valves in the event of a leak, and extensive pressure testing ^[1]. Having said this, the crucial role of a chemical injection pump cannot be overstated.

What is the primary intention of a typical pump chemical injection package? How do these units function? What situations are they capable of addressing? These are some of the questions which will be addressed throughout the remainder of this article.

What is a Chemical Injection Pump?

The core purpose of a chemical injection pump is to guarantee the operational efficiency of an oil or gas pipeline. A typical chemical injection pump addresses three primary concerns during normal conditions:

• Corrosion
• Flow rate
• Well productivity

Corrosion is particularly relevant, as it can negatively impact the other two conditions subsequently mentioned. Furthermore, corrosive elements will continue to cause damage until they are completely removed ^[2]. This may even result in a structural failure; halting production altogether.

A chemical injection pump is therefore employed in a proactive manner in order to monitor the condition of the pipeline as well as to insert specific anti-corrosive and flow-enhancing elements at predetermined times.

The Different Types of Chemical Injection Pumps

It is also important to note that there are two primary chemical injection pump configurations:

• Gas-driven pumps
• Electric pumps

A positive displacement chemical injection pump (sometimes referred to as a diaphragm pump) utilises gas pressure during their operation. The amount of pressure is directly correlated with the length of the stroke. Note that these are generally suited for lower flow rates and higher levels of viscosity. This type of chemical injection pump is often found at the upstream portion of a refinery ^[3].

Electric pumps employ one or more pistons during their operation. One of their primary benefits is that they prevent a closed system from venting gas. Furthermore, both AC and DC power sources can be utilised. An electric chemical injection pump can likewise provide sustainable benefits (such as via the use of solar power) and IoT-powered systems offer a greater degree of user control; ideal in terms of both safety and efficiency ^[4].

What Types of Chemicals Will These Pumps Supply?

As already mentioned, a chemical injection package oil and gas sector is intended to maintain structural integrity. Corrosion will frequently impact pipelines made from metals such as copper, stainless steel, carbon steel, and cast iron. Other variables that may impact rates of corrosion include flow rates, dissimilar metals within the system, and oxygen content. As a result, issues such as leaching, pitting and galvanic corrosion may lead to substantial problems ^[5].

A chemical injection pump will therefore dampen the short- and long-term effects of corrosion through the use of specific compounds. Some of the most common chemicals that can help to augment pipeline safety include:

• De-salting agents.
• Solvents.
• Biocides.
• Scale inhibitors.
• Oxygen scavengers.
• Surfactants.

Note that chemical injection pump manufacturers may also develop proprietary formulations based around the needs of the client in question.

SCADA Systems and Chemical Injection Pump

The automated nature of a chemical injection pump dictates that many of its processes are controlled by on-site or remote computers. One effective method involves the use of a SCADA System (Supervisory Control and Data Acquisition) framework. Some of the advantages specifically relevant to the petrochemical sector include ^[6]:

• Redundancy in the event of a single system failure.
• Limited end-user interaction.
• Intelligent reporting techniques.
• Increased throughput
• These systems can often be tailored to suit the needs of a specific customer

Simply stated, a chemical injection pump will use SCADA architecture in order to guarantee superior levels of safety and reliability.

What Challenges Does the Chemical Injection Pump Sector Face?

Although a modern chemical injection pump is extremely effective at reducing pipeline corrosion, emission rates are still concerns. A study conducted by the Environmental Protection Agency (EPA) found that the emission-reducing efficiency of a pump can be affected by variables such as frequency of operation, unit size, inlet methane characteristics, and gas pressure ^[6]. Thus, it is always important that the most appropriate chemical injection pump is selected.

Modern Solutions for Challenging Times

It is impossible to overstate the positive effects that a chemical injection pump can have within the petrochemical sector. However, it also needs to be mentioned that governmental guidelines such as emissions standards and safety protocols may dictate that the design and implementation of these pumps need to be modified in the future. However, the on-site benefits of a chemical injection pump clearly dictate that they are indispensable in this day and age.