Chemical Injection Skid Manufacturer in India: Oil and Gas Applications Guide

What is a Chemical Injection Skid?

A chemical injection skid (also called a chemical injection package or CIP) is a fully assembled, skid-mounted system designed to store a treatment chemical and inject it precisely into an oil or gas production system at a controlled rate. Chemical injection is fundamental to flow assurance and asset integrity management in oil and gas production — it prevents the corrosion, scale deposition, hydrate blockage and bacterial growth that cause pipeline failures, well shut-ins and costly interventions.

Premix Technologies designs and manufactures chemical injection skids for upstream oil and gas, midstream gas processing, gas export pipelines and refinery utility applications from our facility in Ahmedabad, India. We have supplied chemical injection skids to ONGC, Reliance Industries and other Indian oil and gas operators, and export to the Middle East, Southeast Asia and Africa.

Types of Chemical Injection Skids for Oil and Gas

Corrosion Inhibitor Injection Skid

Corrosion inhibitors protect the internal surfaces of carbon steel pipelines and process equipment from electrochemical corrosion caused by CO2, H2S, water, oxygen and organic acids. The corrosion inhibitor injection skid meters inhibitor into the production line at a continuous low dose rate — typically 10-100 ppm — based on the water cut, CO2 partial pressure and pipeline operating conditions. High-accuracy hydraulic diaphragm pumps or plunger pumps are used to ensure consistent delivery against the pipeline operating pressure.

For sour service pipelines (H2S above 0.0035 MPa partial pressure), all wetted components must comply with NACE MR0175/ISO 15156. SS316L is the minimum standard; for high H2S service, Duplex SS 2205 or Alloy 625 wetted parts may be required.

Scale Inhibitor Injection Skid

Scale inhibitors prevent the deposition of calcium carbonate, calcium sulphate, barium sulphate and strontium sulphate scale in production tubing, flowlines, subsea equipment and heat exchangers. Scale blockage is a major flow assurance concern in fields producing water with high hardness, alkalinity or sulphate content. Scale inhibitor is dosed continuously at very low rates — typically 5-50 ppm — requiring high-accuracy, low-flow injection pumps with tight stroke repeatability.

For deepwater and high-temperature applications, thermally stable phosphonate or PPCA scale inhibitors are specified. The injection skid must deliver chemical reliably against wellhead pressures of 100-700 bar, requiring hydraulically actuated diaphragm pumps or high-pressure plunger pumps.

Methanol Injection Skid

Methanol is injected into gas wells, flowlines and export pipelines to prevent hydrate formation — a dangerous blockage caused when water vapour and natural gas combine at high pressure and low temperature to form an ice-like solid. Methanol injection is the primary hydrate inhibitor strategy for onshore and shallow-water gas production in India.

Methanol injection skids handle significantly larger volumes than corrosion inhibitor or scale inhibitor skids. A typical gas well methanol skid may inject 5-50 litres per hour continuously during winter or cold ambient conditions. The storage tank is typically 500-2000 litres. Because methanol is a flammable liquid, the injection skid must be ATEX/IECEx certified with explosion-proof motors, intrinsically safe instrumentation and earthing provisions.

Biocide Injection Skid

Biocides kill sulphate-reducing bacteria (SRB) and other microorganisms that cause microbiologically influenced corrosion (MIC) and reservoir souring — the conversion of sulphate to H2S by bacterial activity in the reservoir. Biocide injection is typically intermittent (batch) rather than continuous — a concentrated slug dose is injected weekly or monthly at a high enough concentration to achieve a kill dose throughout the system.

Biocide injection skids include a large-volume storage tank (typically 1-5 m3), a high-pressure pump for batch injection, a batch timer or PLC controller and robust corrosion-resistant wetted parts. Because biocides are often toxic, the skid must have secondary containment and appropriate safety provisions for chemical handling.

Oxygen Scavenger Injection Skid

Oxygen scavengers chemically react with dissolved oxygen in injection water, produced water, seawater lift systems and utility water to neutralise it before it causes corrosion. Even trace dissolved oxygen (below 10 ppb) can cause significant corrosion in high-pressure carbon steel systems. Sodium bisulphite and DEHA are the most common oxygen scavenger chemicals. The injection skid injects scavenger into the water stream before it enters the pipeline or process equipment.

Key Design Standards for Chemical Injection Skids

Chemical Injection Skid Components

• Chemical storage tank: SS316L, HDPE or FRP day tank (200-2000 litres) with level gauge, high-level and low-level alarms. Bunded for secondary containment on the skid frame.
• Injection pump: Plunger pump or hydraulic diaphragm pump (API 675) sized for the required injection rate and system pressure. Redundant (duty/standby) pump configuration for critical continuous injection duties.
• Injection quill: SS316L, Hastelloy or Duplex SS injection quill delivering chemical to the pipeline centreline. Fixed or retractable design depending on pipeline pressure.
• Pressure safety valve: Protects the pump and discharge piping from overpressure in the event of a blocked injection line or closed isolation valve.
• Check valve: Prevents backflow of produced fluid or gas into the chemical injection line when the pump is not running.
• Instrumentation: Pressure gauges, pressure transmitters, stroke counter or flow meter, level transmitter and low-level alarm.
• Control panel: From simple local panels with push-button start/stop to full PLC automation with remote monitoring, alarm management and integration with the plant DCS or SCADA system.
• Skid frame: Structural steel frame with drip tray for secondary containment. All components assembled, piped and wired. Pressure-tested before delivery.

Premix Technologies Chemical Injection Skids for Indian Oil and Gas

Premix Technologies has supplied chemical injection skids for corrosion inhibitor, scale inhibitor, methanol, biocide and oxygen scavenger service to oil and gas projects in India including ONGC and Reliance Industries operations, and exports to the Middle East and Southeast Asia. Our skids are supplied with complete engineering documentation including GA drawing, P&ID, datasheet, equipment list, test certificates and operation manuals.

Contact our engineering team at sales@premixtechnologies.com with your chemical type, injection rate, operating pressure and site area classification for a chemical injection skid design and quotation. View our oil and gas industry solutions and chemical dosing systems range.

Related Products from Premix Technologies

• Chemical Dosing Systems
• Methanol Injection Packages
• Corrosion Inhibitor Injection Packages
• Plunger Dosing Pumps
• Injection Quills
• Oil and Gas Industry Solutions