Upstream · Solutions & products
Enhanced oil recovery (EOR)
Go after the barrels that mature fields leave behind. Enhanced recovery with local inputs (natron/neem ASP, CSS) and the revival of marginal blocks — more value from the same subsoil.
The additional barrel · interactive
Every point of recovery is more crude.
Enhanced recovery (EOR) goes after the crude that primary production leaves in the reservoir. Vary the targeted recovery gain and measure the additional barrel.
Reference reservoir: 500 Mbbl in place (illustrative). Values are teaching orders of magnitude — company in formation.
Browse this page · 3 themes
Recover up to 17 more points of OOIP per reservoir.
Primary and secondary recovery only extract 20-35% of the oil in place (OOIP). On Doba’s heavy crudes (21-24° API), EOR combined with modern technologies — advanced chemistry, intelligent lift, AI-driven drilling — is the decisive lever of the national 250,000 barrels/day plan: extending the life of mature fields without new drilling, and unlocking the billions of trapped barrels.
ASP — Alkali / Surfactant / Polymer
Injection of natron (Na₂CO₃, a local Chadian resource), surfactants and biopolymers to lower interfacial tension and sweep residual crude. Targeted for the Doba basin.
CSS — Cyclic steam stimulation
Cyclic steam injection to thin heavy, viscous crudes and improve their mobility. Target: the heavy crudes of Doba and biodegraded zones.
WAG & gas injection
Water-alternating-gas (WAG) injection putting today’s flared associated gas to work — in synergy with Sustainability (site gas-to-power, for our operations). Pilot phase.
Why EOR is the best barrel
A barrel recovered through EOR costs 2 to 4× less than a barrel from new exploratory drilling: the surface infrastructure, wells and pipeline already exist. On declining mature fields, it is the most profitable and least risky capital.
The national objective of lifting production to 250,000 b/d by 2030 — +74% over the ~144,000 b/d of 2024 — rests largely on EOR at the mature fields of Doba and Bongor — not only on exploration of the northern basins.
What if EOR additives came from Chadian soil?
ASP processes rely on costly imported chemicals. Yet Chad holds natural resources directly usable as EOR inputs — cutting import dependence, creating rural value chains, and anchoring industrial autonomy.
Natron → alkaline agent (the A in ASP)
Locally mined natron as the alkaline agent for ASP injection, replacing imported sodium carbonate. Its buffering effect lowers interfacial tension with less rock damage than NaOH.
Gum arabic → biopolymer
Polysaccharide base for xanthan-type biopolymers offering superior stability in high-salinity/high-temperature reservoirs where synthetic HPAM fails. Supports 500,000+ rural households.
Cotton cellulose → polymer (P)
Chadian cotton (250,000 ha, 2.5 M workers) supplies pure fibres. Low-grade cotton converts into cellulosic polymers (CMC, HEC) for viscosity control, replacing petroleum-based polyacrylamide.
Neem & shea → biosurfactant (S)
Feedstock for biodegradable surfactants cutting interfacial tension by up to ×1,000 to mobilise oil. Combined with alkaline natron in an ASP formulation, they reach 27%+ ROIP recovery.
Spirulina → microbial EOR (MEOR)
Lake Chad spirulina (the world’s lowest-cost producer) contains cyanobacteria capable of biosurfactant synthesis. A MEOR pilot pathway for in-situ surfactant generation in Doba’s mature wells.
CO₂-EOR → CCUS
Carbon capture and utilisation pilot for CO₂-EOR (miscible injection). CO₂ captured at gas processing sites feeds the pilot. Permanent geological storage under study.
Six Chadian inputs, read as an EOR formulation.
Each resource is positioned by its role in ASP chemistry (Alkali · Surfactant · Polymer), its physical mechanism, its geographic origin and the import it replaces. Maturity remains indicative — R&D objectives, no deployment to date.
ASP additives account for a large share of an EOR project’s cost. Sourcing them locally means less foreign currency leaving the country and rural value chains created.
Purification, batch standardisation and performance under reservoir conditions (temperature, salinity) — the focus of the Petrochemicals R&D programme.
Agricultural/mineral harvest → purification → ASP formulation → core-flood tests → field pilot on heavy fields.
Borkou natron, gum arabic (world no. 2), cotton cellulose, neem/shea biosurfactants, Lake Chad spirulina, and CO₂ captured at the refinery: six pathways to 100% Chadian EOR inputs. Cutting import dependence and creating downstream value from our agricultural and mineral wealth.
Industrial natron sourcing (Borkou/Lake Chad), ASP pilot on 3 Doba wells, CSS feasibility study on Doba heavy crudes.
Cotton-cellulose polymer plant, neem/shea biosurfactant laboratory, spirulina MEOR screening, thermal EOR pilot on Doba heavy crudes.
Full ASP deployment on 50+ Doba wells, thermal EOR on heavy crudes, EOR chemical manufacturing unit (Petrochemicals), 100% local sourcing objective.
Produce more, from the existing heavy fields.
Doba’s heavy crude (21-24° API) is viscous and hard to mobilise. EnerTchad combines the latest recovery technologies — advanced chemistry, intelligent lift, AI-driven drilling and digital twins — to raise the recovery rate of mature fields, without waiting for new discoveries.
ASP systems reinforced with emulsifying surfactants and polymers: crude viscosity drops by more than 90%, improving cold mobility — less energy and fewer emissions than thermal methods.
Biopolymers and nano-additives that stay stable in hot, saline environments where conventional polymers fail — a wider, longer-lasting reservoir sweep.
Electric progressive-cavity pumps, designed for heavy crude, driven by a digital platform: better recovery, lower OPEX and longer equipment life.
AI-guided directional drilling and instrumented wells (downhole sensors): more precise trajectories, maximised reservoir contact and drilling speed improved by up to +30%.
Matrix acidising and fracturing to restore and improve permeability around the well: clogged drains are reopened and mature-well productivity is revived at low cost.
Cyclic steam injection (huff-and-puff) to heat and thin the heavy crude around the well, then produce it: a recovery gain of +20 to 50% in Doba’s most viscous zones.
A digital replica of the field to test production scenarios and predict yield before going to the field — in liaison with our R&D & Technology department.
Injection of CO₂ captured at the refinery to mobilise residual crude: additional recovery paired with geological carbon storage. Under study.
An EOR formulation fed by Chad’s subsoil.
Where conventional EOR imports its chemicals, EnerTchad draws on local resources: Kanem natron as the alkali, gum arabic (Chad is Africa’s no. 2 producer) and shea derivatives as bio-based surfactants, completion brines drawn from Lake Chad’s natural brines. Recovery chemistry that is cheaper, less dependent and rooted in the territory.
Alkali (Na₂CO₃) for pH control and interfacial tension reduction.
Bio-based surfactants and fluid-loss agents, an alternative to synthetic surfactants.
Natural Lake Chad brines (200-350 g/L) replacing imported synthetic brines.
EnerTchad offers its heavy-crude EOR expertise as a service to other operators in Chad and CEMAC — a unique regional centre of expertise, through technology JVs and billed pilots.
Oilfield services offerChad’s subsoil holds what the industry imports.
Wyoming bentonite, Gulf cement, North American proppants: every chemical input crosses three continents before reaching the wellhead — logistics accounts for up to 40% of the delivered price. EnerTchad reverses the equation: extract, process and formulate locally the 9 families of raw materials found on the territory, to build Central Africa’s first integrated petroleum chemistry industry.
Industrial autonomy
Produce locally what the subsoil holds in abundance. Reduce import dependence and create a petroleum chemistry pole that did not exist before.
Economic competitiveness
A tonne of imported bentonite exceeds 800 USD delivered to N’Djamena; activated locally, it comes to ~350 USD. Over 20 wells, the savings run into millions of dollars.
Circular economy
Produced water, flared gas and agricultural residues stop being losses and become inputs. The Water-to-Value™ turns the biggest cost item into a revenue source.
The nine families of raw materials
Spread across the whole territory, each answers a specific need of the chemical chain — from drilling fluids to enhanced recovery.
Completion brines (NaCl/KCl/CaCl₂), natron. Chloride content 200-350 g/L. Cost: 40-60% of the import price.
Class G/H oil-well cement (CaCO₃ > 95%, API 10A standard). Cement = 8-12% of a well’s cost.
WBM drilling muds. Enslin swelling 600-900%. Sodium activation → API 13A standard. Savings 55-65%.
Fracturing proppants (SiO₂ > 98%, sphericity 0.7-0.8, mesh 20/40 & 30/50). Removes 15-25% of stimulation cost.
Water treatment, pH control, H₂S neutralisation, soil stabilisation. Calcination at 900–1,100 °C.
Setting regulator for oil-well cement (3-5% dosage). Weighting agent and field construction materials.
Gum arabic (Africa’s no. 2 producer): bio-based EOR surfactants, fluid-loss agents. Bioenergy for camps.
Gas-to-power, blue hydrogen (SMR), ORC. GOR 200-600 scf/bbl, > 80% flared today. Zero-flaring objective 2030.
Water-to-Value™: de-oiling, salt extraction, reinjection, irrigation. Water cut > 85% at Doba. Zero-discharge objective.
Six integrated petro-industrial chains
The nine families feed six processing chains covering all the chemical needs of the Chadian upstream.
Kanem brines → KCl/CaCl₂/CaBr₂ fluids and workover brines. Short supply loop on the Lake Chad basin.
Activated Salamat bentonite + Guéra lime + natural additives = complete WBM muds formulated locally.
Ennedi silica sand, graded and resin-coated for fracturing. Cuts stimulation cost by 20-30%.
HPAM polymers, cross-linked gels, bio-based surfactants (gum arabic, shea derivatives), chemical tracers. Tertiary recovery at Doba.
Quicklime for flocculation, de-oiling, membranes, reinjection. Water-to-Value™: salts recovered, water reinjected or used for irrigation.
Associated gas → electricity, blue hydrogen (SMR), methanol, heat (ORC). The end of flaring becomes a profit centre.
Roadmap 2026 → 2032
Deposit characterisation. First batches of activated bentonite and brines tested on Doba worksites.
Processing units: bentonite (5,000 t/yr), proppants (2,000 t/yr). First bio-based EOR pilots.
Six chains operational. Substitution of 60-70% of imported inputs. Water-to-Value™ on 3+ fields.
The first local petroleum chemistry hub, replicable towards Niger, Cameroon and CAR.
Technical data from the EnerTchad Exploration & Production White Paper (Raw material valorisation, 2026). Deposit figures and savings are estimates, to be confirmed by characterisation.
Quality & product partnerships · Petrochemicals pole
Co-development of EOR inputs, batch quality control and the targeted certifications (ISO 9001, supplier qualification) are steered by the Petrochemicals pole — a single quality chain for the farmer’s field and the well.
Product partnerships & quality — on the Petrochemicals side →Continue in Exploration & Production
A picture is worth a thousand barrels: side by side, what conventional recovery leaves in the rock — and what EOR goes after.
↔ Scroll the diagram horizontally.
EOR · The science, step by step
Why oil stays trapped — and how we go and get it.
After decades of production, most of the crude is still in the rock: held by capillary forces inside the pores, bypassed by injection water more mobile than the oil itself. EOR is not magic: it is the physics of interfaces and flow, applied pore by pore.
Droplets held prisoner in the pores
At pore scale, the water-oil interfacial tension (20 to 30 mN/m) locks residual crude into droplets that injection pressure alone cannot dislodge. This is “residual” oil — invisible to the drill bit, immense at basin scale.
Nc = μ·v / σ — the key to mobilisation
Setting residual oil back in motion means raising the capillary number by a factor of 100 to 1,000 — which means crushing the interfacial tension σ. That is the job of surfactants: at 10⁻³ mN/m the droplets coalesce and form a mobile oil bank.
M ≤ 1: sweeping without fingering
Water that is too thin “fingers” through viscous crude and leaves whole swathes of the reservoir untouched. Thickening the water with polymer brings the mobility ratio back below 1: the injection front becomes a steady piston that pushes the oil instead of going round it.
The alkali makes soap inside the rock
Doba heavy crudes are rich in naphthenic acids. On contact with an alkali — natron — those acids turn into natural surfactants, directly in the reservoir: part of the chemistry is produced by the crude itself, reducing the surfactant volume that has to be injected.
The right EOR is chosen in the data, not in the catalogue.
Every method has its application window — crude gravity, viscosity, depth, temperature, permeability. The criteria below (standard industry screening grids, indicative) place the Doba basin: the reservoir study, then the pilot, are what decide.
| Criterion | Polymer / ASP | Steam (CSS) | WAG · gas |
|---|---|---|---|
| Crude gravity | > 15° API | 8-25° API | > 22° API |
| In-situ viscosity | < 150 cP (modern HPAM: higher) | > 200 cP — its home ground | < 10 cP |
| Depth | < 2,700 m | < 1,400 m | depends on miscibility pressure |
| Temperature | < 90 °C | not a constraint | not a constraint |
| Permeability | > 50 mD | > 200 mD | not a constraint |
| Doba basin · 21-24° API, shallow sandstones | Core target ✓ | Most viscous zones ✓ | Study · subject to associated gas |
Indicative windows (standard industry screening grids) — the final selection rests on reservoir studies and pilots. Company in formation.
Four Chadian materials, a sovereign EOR chemistry.
EOR consumes tonnes of alkalis, polymers and surfactants — imported everywhere else. Chad produces the four key raw materials. Qualifying them for the reservoir is EnerTchad’s signature R&D programme: less hard currency leaving the country, a Chadian agricultural supply chain that gets paid, and know-how that stays.
Sodium carbonate from Kanem
Harvested on the shores of Lake Chad for centuries, natron (Na₂CO₃) is the “A” in ASP: it triggers in-situ saponification and shields surfactants from adsorption onto the rock.
Role: ASP alkali · Status: laboratory characterisation targetedAcacia biopolymer, water thickener
Chad is among the world’s leading producers of gum arabic. A viscosifying polysaccharide, it is being studied as a bio-sourced alternative to the imported polyacrylamides (HPAM) used for mobility control.
Role: viscosifier · Status: TchadiTech R&D, laboratory validationCMC: viscosity and filtrate control
Derived from Chadian cotton, carboxymethyl cellulose is a standard additive in oilfield fluids — a viscosifier and filtrate reducer for muds, and a complement to injection formulations.
Role: fluid additive · Status: industrial supply chain targetedPlant-based biosurfactants and inhibitors
Neem extracts, abundant in Chad, are studied by the industry as natural surfactants and green corrosion inhibitors — a building block of EnerTchad’s “low impact” formulation.
Role: green surfactant · Status: watch & exploratory trialsThe virtuous circle. Every tonne of qualified local input replaces an import paid in hard currency, pays a Chadian agricultural supply chain (gum, cotton, neem) or an artisanal one (natron), and builds chemical expertise that can be exported across CEMAC. The method stays honest: laboratory validation, then single-well pilot, then inter-well — each step published in our Carnets.