Chemical injection block is designed for the metered injection of liquid demulsifiers and corrosion inhibitors into the gathering and process system pipeline for oil demulsification inside pipeline as well as protecting pipelines and equipment from corrosion, wax deposits, etc. Chemical injection block UDH (BDR) is designed for chemical treatment of wellstream fluid in the gathering, transport and processing systems. It is used on wellpad sites, booster pump stations and processing facilities.

Chemical Injection block consists of technological and hardware rooms

Technological room of the chemical injection block includes:

·         Injection pump which performing continuous volumetric dosing of liquid demulsifiers and corrosion inhibitors;

·         Dosing electric, plunger or membrane units performing continuous volumetric dosing of the chemical;

·         A gear pump, filling the process tank with a chemical reagent and periodically mixing the reagent in a container;

·         Rectangular welded container is designed for the dosed injection of a certain volume of liquid demulsifiers and corrosion inhibitors into the pipeline for a regulated period of time;

·         Technological non-pressurized welded tank with rectangular section designed for storage and reagent heating, equipped with an electric heater, a visual level indicator with measuring ruler, limit level sensors, filler neck with a filter and breathing hole;

·         Instrumentation for parameter control and control posts

 

The control cabinet (insulated with electric heating) is mounted in the hardware room of the chemical injection unit. Its functions are:

·         Automatic filling of the technological tank with chemical agent and automatic shutdown of the gear pump when filling the tank;

·         Cyclic mixing of the chemical and maintaining its temperature within the specified limits;

·         Local control of the pressure and temperature of the chemical;

·         Automatic temperature control with electric heater installed in the tank;

·         Automatic control of the temperature by electric heating in the control cabinet;

·         Manual local control of injection pumps, fan, electric heaters, lighting;

·         Automatic shut-off of metering pumps at pressure increase and chemical agent minimum level;

·         Maintaining the air temperature in the rooms of the block-box within the specified limits;

·         Indicating the emergency condition of technological equipment;

·         Protection of technological and hardware room lighting  from short circuit;

·         Control over the technological equipment of various modifications with the possibility of remote control and block connection to the process control system of the upper level.

Electrical equipment and instrumentation tools used have explosion-proof design, wires and cables are copper.

 

Chemical injection block has different designs depending on:

1) the performance of injection pump and its type;

2) Number of injection pumps;

3) Availability and quantity of tanks;

4) Presence of cabinet or control block;

5) Presence of controller;

6) Presence of flowmeter.

Chemical injection black modifications:

Design version		Design		Layout
		General industrial	Explosion-proof
I	TB	+		Mounted on one frame
	Hardware block AB	+
II	TB		+	Stand-alone hardware block AB located in the same room or on one frame outside the hazardous area
	Hardware block AB	+
III	TB		+	Stand-alone hardware block AB located in the same room or on one frame outside the hazardous area
	Hardware block AB		+

TB-technological block

AB-hardware block

The main advantages of the chemical injection unit:
- filters in the intake line of each metering pump
- filter in the injecting pipe inside the tank;
 - convenient performance setting of the metering pumps
- containers for collecting leaks from metering pumps
- pump cleaning lines are installed in the methanol injection blocks.

To differentiate chemical injection blocks with different characteristics the following code is used:

Chemical injection block BDR (1) - X(2) - X(3) - (X)(4) - X(5); (X)(6) - X(7) - U(8)
1 - Number of block
2 - Working pressure, MPa
3 -  Number  of injection pumps
4 - Maximum performance of the pump
5 - Number  of internal containers
6 - Volume of the supply tank,  m³
7 - Volume of external tank, m³ (if available)
 8 - "U" - control block on the common frame with injection block (if control block is present)

Code example of chemical injection block at ordering: Chemical injection block, working pressure 10 MPa, the number of pumps 2 with a  maximum performance 10 L/h, internal tank 1 with volume of 2 m³,  external tank 1 with volume of 6 m³, control block on a common frame with chemical injection block:

Chemical injection block BDR-10-2(10)-1(2)-6-U

Stand-alone hardware block AB located in the same room or on one frame outside the hazardous area