Retention Economics — Surfactant EOR Screening Model
Interactive screening companion
Appearance
Live readoutPOSITIVE SCENARIO NPV
NPV
—
IRR
—
vs dr hurdle
Unit tech. costUTC
—
Breakeven retention Γ*Breakeven Γ*
—
Screening variables — primary
0.155 mg/g
0.520
$55/bbl
Surfactant EOR · HTHS carbonates
Retention Economics — Surfactant EOR Screening Model
An interactive discounted-cash-flow screening model that resolves surfactant dynamic
retention, Γ, into project value for chemical flooding in high-temperature, high-salinity carbonate
reservoirs. The retention–recovery relation is fitted to twelve SAMPLE screening records and is applied only
inside the calibrated window Γ = 0.095–0.310 mg/g-rock. At the scenario specified in Section 2 the model
returns NPV = —, an internal rate of return of
—, a breakeven retention Γ* = —,
and a breakeven oil price of —. Chemical spend is fixed by slug design
and not by retention, so each additional milligram retained per gram of rock removes incremental barrels
while the injected chemical cost holds constant.
SAMPLE Computed in the browser from the screening records in Section 1
—
NPV
—
IRR · vs dr hurdle
—
Unit tech. cost
—
Breakeven retention Γ*
Interactive companion to the manuscript Techno-economic Screening of
Surfactant Flooding in High-Temperature, High-Salinity Carbonates under Retention Uncertainty
by Imad A. Adel and co-authors — under review at Petroleum Research. The manuscript and its data workbook are not distributed from this page.
HOW TO USE
What this is
An interactive implementation of the screening model developed in the accompanying manuscript.
The page loads a SAMPLE base case — fitted retention–recovery
relation, Γ = 0.155 mg/g-rock, oil price $55/bbl. The SAMPLE records reach the same
screening conclusions as the manuscript with different values; the measured records are not
published here.
Parameters
Every input lives in the Scenario parameters pane. Change one and each figure, the abstract
values, and the live readout recompute against the edited scenario.
Recovery-factor basis
The fitted relation RFlab = A·e−kΓ is the default and holds only over
Γ = 0.095–0.310 mg/g-rock. Manual RF input substitutes an entered value for scenario testing; recovery
then decouples from Γ and breakeven retention reads n/a. Sweep efficiency and the saturation ratio
scale RFlab to field basis in both modes.
Figures are interactive
Hover for exact values, drag to zoom, double-click to reset the axes, and use the camera icon to
download a PNG. Figures re-render as parameters move.
Export and reset
Export scenario downloads a text file of all inputs and computed outputs. Reset base case
restores the defaults.
Where things are
Parameters in the Scenario parameters pane, results figures in the Results panes,
assumptions and limitations in the Assumptions and limitations pane.
Scenario recordSAMPLE scenario
Scroll across to inspect every column.
Prepared by
Imad A. Adel
Subject
Surfactant EOR · HTHS carbonates
Basis
n = 12 SAMPLE records · calibrated Γ 0.095–0.310 mg/g · SAMPLE
Scenario status
BASE CASE
Summary of results — current scenariobase case
NPV
—
IRR
—
vs dr hurdle
Incremental oil
—
Unit tech. cost
—
Payback
—
discounted, interpolated
Breakeven retention Γ*
—
Section 01 · Basis and benchmark
Basis and benchmark
A discounted-cash-flow screening model that maps surfactant dynamic retention (Γ) directly to project
value for chemical flooding in high-temperature, high-salinity carbonate reservoirs. Calibrated on a set of twelve SAMPLE screening records, it resolves the retention, oil-price, and sweep thresholds
at which NPV crosses zero.
Prepared by Imad A. Adel
Stage A — Recovery
Twelve SAMPLE screening records (SP and ASP, 80–95 °C, up to 144,000 ppm TDS)
collapse onto a single exponential decay of recovery with dynamic retention, scaled to field conditions
through sweep efficiency and the saturation ratio.
Stage B — Cash flow
Chemical spend is set by slug design (ASP + two polymer drives), not by retention — so every extra
milligram retained erodes barrels while cost stays fixed. A five-year uniform cash flow is discounted at
10% against upfront capital.
Stage C — Thresholds
Bisection root-finding resolves the breakeven retention, breakeven oil price, and sweep-efficiency
threshold where value crosses zero, and one-at-a-time sensitivity ranks the engineering levers that move
NPV the most. At the current scenario Γ* solves NPV(Γ*) = 0 at
—.
Screening benchmark — SAMPLE records (n = 12)Γ 0.095–0.310 mg/g
Scroll across to inspect every column.
SAMPLE screening records: retention, recovery, formulation, core type, temperature and total dissolved solids.
Fig. 1 — SAMPLE screening records & retention-decay fit. Recovery
(% Sorw) against dynamic retention for the SAMPLE screening set: circles are ASP
records, diamonds are SP records, and the solid curve is the fitted exponential
RFlab = ARF·e−kRF·Γ evaluated at the coefficients of Section 2.
The shaded band marks the calibrated domain Γ = 0.095–0.310 mg/g-rock; the open marker is the current
operating retention.
n = 12 · R² = 0.989
Governing equationsSAMPLE scenario
Calibrated domain. The exponential RF fit is empirical and valid only within the calibrated
retention range (0.095–0.310 mg/g-rock); those two values are the minimum and maximum dynamic retentions
in the SAMPLE record set. Evaluations outside that interval are extrapolations of the fitted relation and
carry no support in the record set. The model flags any such evaluation in Section 2 and on the incremental-oil
readout.
Section 02 · Scenario parameters
Scenario parameters
The specification below opens at a SAMPLE base case.
Every field is editable, and each figure, table and readout on this page recomputes from these values.
Retention Γ, volumetric sweep Ev and oil price are the screening variables and carry sliders;
the remaining fields are entered numerically. Pressure, temperature and salinity enter only through the
screening criteria applied to the records, not as model inputs.
Prepared by Imad A. Adel
Screening variables — primaryΓ mg/g-rock · Ev fraction · $/bbl
%Sorw
0.155 mg/g
0.05calibrated 0.095–0.3100.40
0.520
0.40breakeven ≈ —0.75
$55/bbl
35constant price over project life95
Γ OUTSIDE CALIBRATION
Retention Γ = — mg/g-rock lies outside the calibrated interval
0.095–0.310 mg/g-rock. The exponential recovery fit is extrapolated beyond the SAMPLE record set and the
outputs below are indicative only.
At Γ = — mg/g-rock the fitted relation returns
RFlab = — % Sorw and
RFfield = — % OOIP. Applied to an OOIP of
— MMstb this gives ΔNp =
— MMstb and gross revenue of
— at —.
Chemical, injection and production operating cost total —;
CAPEX of — is charged at year zero. The uniform annual cash flow
of — over — years discounts at
— to NPV = —.
Fig. 2 — Discounted cash flow profile. Bars are annual discounted cash flow
in $MM, the line is cumulative discounted cash flow, and the dotted vertical marks the discounted payback
intercept obtained by linear interpolation between the bracketing years. Year 0 carries CAPEX as a lump sum.
Fig. 3 — Value composition — revenue to NPV$MM · pre-tax · constant 2026 USD
Fig. 3 — Value composition — revenue to NPV. Gross revenue is
reduced in sequence by chemical cost, injection operating cost, production operating cost, the discounting
term, and CAPEX; the closing bar is NPV. All quantities in $MM, pre-tax, constant 2026 USD.
Section 04 · Retention economics
Retention economics
Chemical mass injected is set by slug size and concentration and does not vary with Γ. Retention therefore
acts only on the recovery term, and NPV falls monotonically with Γ at fixed slug design. The
crossing point is resolved by bisection on Γ ∈ [0.01, 1.0] mg/g-rock to a tolerance of 10−8.
Prepared by Imad A. Adel
Fig. 4 — Project value and rate of return against dynamic retentionshared retention axis
Fig. 4 — Project value and rate of return against dynamic retention, shared
retention axis. Panel (a) is NPV in $MM, filled to the zero line; panel (b) is the internal
rate of return in per cent, capped at 120%. Both panels sweep Γ = 0.05–0.40 mg/g-rock with every other
parameter held at the Section 2 specification. The vertical rule crossing both panels is the breakeven
retention Γ* at which NPV = 0; the open markers are the current scenario.
Breakeven retention
At — the breakeven retention is Γ* =
—. The scenario operates at Γ =
— mg/g-rock, —
Section 05 · Viability map
Viability map
The response surface is evaluated on a 55 × 55 grid spanning Γ = 0.05–0.40 mg/g-rock and oil price
35–95 $/bbl, with every other parameter held at Section 2. The zero contour separates the viable and
uneconomic domains and is the locus of the Γ* and P* roots reported elsewhere on this page.
Fig. 5 — NPV response surface — retention × oil price.
Filled contours of NPV in $MM over the retention–price plane; white contour = breakeven
(NPV = 0) · marker = current scenario. Warm fill denotes negative NPV.
Section 06 · Risk
Risk
Each parameter is moved to its low and high bound in isolation while all others stay at the current
scenario. Bounds are SAMPLE ranges about the SAMPLE base case. Bars are ordered by span, so the ranking is the
ranking of parameter influence on NPV at this operating point and not a general ranking.
Fig. 6 — One-at-a-time sensitivity — SAMPLE uncertainty ranges. Each bar
spans the NPV obtained at the low and high bound of one parameter, drawn from the scenario
base marked by the vertical rule. Red is the downside branch, petrol the upside branch.
Section 07 · Cost structure
Cost structure
Full-cycle expenditure is CAPEX plus chemical, injection and production operating cost. The chemical term
is fixed by slug design; injection cost scales with pore volume and the injection factor; production cost
scales with incremental oil. Cost per incremental barrel therefore rises with retention while total spend
stays flat.
Prepared by Imad A. Adel
Fig. 7 — Full-cycle cost structuremass-based chemical split · $MM
Fig. 7 — Full-cycle cost structure. Shares of full-cycle expenditure split by
chemical component (mass-based), injection OPEX, production OPEX and CAPEX; the centre annotation is total
full-cycle expenditure in $MM.
Fig. 8 — Chemical cost per incremental barrel vs retention$/bbl · Γ 0.05–0.35 mg/g-rock
Fig. 8 — Chemical cost per incremental barrel vs retention. Stacked component
cost per incremental barrel across Γ = 0.05–0.35 mg/g-rock in 0.025 mg/g steps: fixed spend ÷ shrinking barrels.
Fig. 9 — NPV improvement waterfallengineering levers from current scenario
Fig. 9 — NPV improvement waterfall — engineering levers from
current scenario. Sweep efficiency raised by 0.05 (capped at 0.90) and retention reduced by 0.10 mg/g-rock
(bounded below at 0.05) applied in sequence from the current scenario; the closing bar is the final sensitivity scenario
NPV.
Section 08 · Breakeven analysis
Breakeven analysis
The breakeven oil price is the root of NPV(P) = 0 solved by bisection on
P ∈ [5, 300] $/bbl. The screening matrix reports model outputs at seven retentions spanning the calibrated
range; the highlighted row is the retention nearest the current scenario.
Fig. 10 — Breakeven oil price envelope vs retention. Oil price at which
NPV = 0 across Γ = 0.05–0.35 mg/g-rock (amber), chemical cost per incremental barrel (petrol,
dashed) and the current oil price (dotted horizontal) for reference. The open marker is the breakeven
price at the current retention.
Screening matrix — outputs across the calibrated retention rangeseven retentions · current scenario highlighted
Scroll across to inspect every column.
Model outputs at seven retentions: field recovery factor, incremental oil, unit technical cost, breakeven oil price, internal rate of return and net present value.
Γ mg/g
RFfield %
ΔNp MMstb
UTC $/bbl
BE price $/bbl
IRR %
NPV $MM
Section 09 · Assumptions and limitations
Assumptions and limitations
Prepared by Imad A. Adel
Assumptions and limitationspre-tax · constant 2026 USD
How this was computed
Every number on this page is computed in the browser from the scenario in Section 2 and the SAMPLE screening records in Section 1. Recovery of waterflood residual oil follows a single exponential fitted to those records and is calibrated over the retention window those records span; a value outside that window is still computed and is marked as an extrapolation. Cash flow is pre-tax and in constant currency, discounted at the stated rate.
Chemical spend follows the slug design, not the retention, so retention moves the barrels recovered and not the chemical bill. That is a property of the model, and it holds whatever records the model is fitted to.
Pre-tax, constant 2026 USD; calibrated retention range 0.095–0.310 mg/g-rock. This is a bounded screening study, not a field prediction.