Associated Gas Recovery &
LNG Liquefaction System
Congo (Brazzaville) -- Jiarou Oilfield
PRIMARY -- Jiarou Oilfield Field Installation
SECONDARY -- Product Output Operations
Project Facts
- Client & Location
- Intl. Oil Operator / Jiarou Oilfield, Congo
- Total Gas Capacity
- 300×10⁴ Nm³/d gas recovery
- LNG Capacity
- 200×10⁴ Nm³/d LNG liquefaction
- Products
- LNG, Propane, Butane, Stable Light HC, Dry Gas
- Manufactured By
- LINSON OIL, Dongying, China
The Jiarou Oilfield -- Context
The Jiarou Oilfield is an oil-producing field in the Republic of Congo (Congo Brazzaville), operated by an international oil company. Like many African oilfields, Jiarou's primary product is crude oil -- but its associated natural gas, produced alongside the crude at the wellhead, represented a significant resource that was not being captured.
Without gas recovery infrastructure, associated gas from oil production is either vented to atmosphere or flared. Venting and flaring waste a recoverable energy resource, generate greenhouse gas emissions, and -- in an increasing number of jurisdictions -- attract regulatory penalties and ESG liability for the operating company.
The Jiarou project was conceived to convert this flared associated gas into marketable products: LNG for road tanker distribution to domestic and regional markets, LPG (propane and butane) for domestic cooking and industrial use, and stable light hydrocarbons for blending or export. The project was structured in three phases, scaling capacity as product markets developed and infrastructure was established.
The Engineering Challenge
What Made This Project Technically and Logistically Demanding
Remote Location Without Established Infrastructure
The Jiarou Oilfield is located in a remote area with limited local manufacturing, engineering, and maintenance capability. All process equipment had to be designed, fabricated, and tested in China, then exported and transported to the site. The equipment had to be designed for reliable field operation with the available local operations team.
Multi-Stage Gas Processing Integration
Converting raw associated gas to LNG and NGL requires a precise sequence of steps. A failure in dehydration affects the LNG cold box; incorrect NGL fractionation affects product value. The process design must anticipate interdependencies and build in margins that accommodate fluctuating oilfield production over the field's producing life.
Multi-Phase Project Execution Continuity
The structured phases required LINSON OIL to maintain engineering and design continuity across time. Each phase built on installed capacity, interfacing with existing equipment, designed to avoid disruption to ongoing operations. Phase II and III equipment had to interface seamlessly with Phase I infrastructure already in service.
The Solution -- Three Phases
NGL Recovery and Dry Gas to Power
Associated gas from the Jiarou Oilfield separators enters the Phase I processing system at wellhead pressure. The gas passes through an inlet separation and conditioning stage -- removing entrained liquid, regulating pressure, and removing water to the dehydration specification.
The conditioned gas then enters the NGL extraction stage, where heavier hydrocarbon components (C3+: propane, butane, and stable light hydrocarbons) are separated from the leaner gas stream by a refrigeration-based condensation process.
The separated NGL is stabilised and dispatched as liquid product. The lean residue gas is delivered to the oilfield's power generation facility, eliminating the need for diesel fuel import for power generation.
Products from Phase I
- › Natural gas liquids (propane, butane, stable light hydrocarbons)
- › Dry lean gas (fuel gas to oilfield power generation)
Expanded Gas Recovery + LNG Liquefaction
Phase II doubled the gas recovery capacity to 200×10⁴ Nm³/d -- accommodating increased oilfield production and previously un-captured gas from additional well connections. A dedicated LNG liquefaction train was added alongside the expanded gas recovery system.
After NGL extraction, the residue gas enters the LNG liquefaction cold box. The cold box uses a refrigeration cycle to progressively cool the gas to approximately -162°C, at which point the methane condenses to liquid form (LNG). The LNG is collected in insulated storage tanks and loaded into cryogenic road tankers for distribution.
The addition of LNG significantly increased the value recovered from the associated gas, making it the primary route to gas monetisation for remote oilfields without pipeline infrastructure.
Additional LNG Capacity
Phase III added a further 100×10⁴ Nm³/d of gas recovery capacity and a second 100×10⁴ Nm³/d LNG liquefaction train -- bringing the total system to 300×10⁴ Nm³/d of gas recovery and 200×10⁴ Nm³/d of LNG liquefaction capacity across the three phases.
The Phase III equipment interfaces with both Phase I and Phase II infrastructure, sharing common inlet separation, utility systems, and product dispatch facilities where possible. The LNG production from Phase III trains combined with Phase II gives the Jiarou Oilfield a significant LNG output volume.
| Phase | Gas Recovery | LNG Capacity | Additional Products |
|---|---|---|---|
| Phase I | 100×10⁴ Nm³/d | -- | NGL; dry gas to power |
| Phase II | 200×10⁴ Nm³/d | 100×10⁴ Nm³/d | Propane, Butane, Stable light HC, LNG |
| Phase III | 100×10⁴ Nm³/d | 100×10⁴ Nm³/d | Additional LNG train |
| Total | 300×10⁴ Nm³/d | 200×10⁴ Nm³/d | Full product slate |
Delivery Scope -- What LINSON OIL Provided
Engineering
- Process design from inlet gas composition and product specification
- Equipment sizing: all vessels, heat exchangers, compressors, columns, and skids
- P&ID development for each process stage
- Heat and material balance
- Export packaging specification
Export and International Delivery
- Export crating per ISPM-15 standard for all wooden packaging
- Equipment preservation for sea freight transit time and tropical storage conditions
- Freight coordination to Congolese port of entry
- Full export documentation: commercial invoice, packing list, bill of lading, certificate of origin, inspection certificates
- Import documentation support for Congo Brazzaville customs clearance
Commissioning Support
- LINSON OIL commissioning engineers at site for initial system start-up
- Process performance verification against design basis
- Operations team training on equipment operation and routine maintenance
Why This Project Matters As A Reference
International Engineering Delivery
This is not a domestic Chinese project cited as an international reference. The equipment was designed in China, fabricated in Dongying, exported internationally, and commissioned at a remote oilfield in Central Africa. Every stage of the international delivery chain -- export documentation, sea freight, in-country customs clearance, and field commissioning -- was managed and executed. The project is internationally deliverable because it has been internationally delivered.
Multi-Phase Project Continuity
The three-phase structure required LINSON OIL to maintain engineering continuity and technical accountability across multiple project phases delivered over an extended period. An equipment supplier who delivers Phase I and disappears leaves the client without continuity for Phase II and III. LINSON OIL delivered all three phases -- maintaining the engineering design continuity, equipment interface compatibility, and commissioning knowledge that multi-phase projects require.
Full Gas Processing Train -- Not Component Supply
LINSON OIL designed and fabricated the complete associated gas recovery and LNG liquefaction system -- not individual components sourced from separate suppliers. The process design, the equipment fabrication, the control systems, and the commissioning were all within LINSON OIL's single scope. For the client, this meant one technical point of accountability for the system's performance -- not multiple vendors pointing at each other when a problem arose.
Scale of Delivery
200×10⁴ Nm³/d of LNG liquefaction capacity across two trains is not a pilot-scale system. This is a commercially operating LNG production facility supplying product to road tanker distribution networks. The engineering, fabrication, and commissioning demands of a system at this scale are substantially more rigorous than those of a smaller demonstration or evaluation installation.
Related Equipment & Systems
Planning an Associated Gas Recovery or LNG Project --
The Jiarou project demonstrates LINSON OIL's capability to design, fabricate, export, and commission a complete associated gas recovery and LNG liquefaction system at a remote international oilfield -- from process brief to operating facility. If your project involves associated gas monetisation, NGL recovery, or small-to-mid-scale LNG in any geography, send us your gas volume and product target. Our engineers will respond with a preliminary system concept and reference within 1-2 business days.