Golden Lane Investments Advisory Group B.V.
Strategic advisory · Petroleum · Energy · Suriname
TECHNICAL SYNTHESIS · GLIAG-TECH-2026-DST-003
The Envelope That Built GranMorgu
Porosity, Permeability and Flow Rate Across Blocks 58, 52 and 53
A reservoir-engineering perspective on the Suriname–Guyana Basin, compiled from public operator disclosures, national oil-company communiqués and independent trade press, 2019–2026.
Author GLIAG — Golden Lane Investments Advisory Group B.V.
Prepared by Drs. M.P.T. Chin-A-Lien, MBA, M.Sc., Ing. Geologist – 12th July 2026
Certified Professional Geologist Nr. 5201-1996 (AAPG) · Chartered European Geologist Nr. 92-1996 (EFG) · Energy Negotiator, June 2021 (AIEN)
Domain Petroleum system geology · Reservoir engineering · DST interpretation
Scope Public-domain synthesis for Suriname-side Blocks 58 / 52 / 53
Prepared Delft, The Netherlands — July 2026
Classification Technical / non-confidential
Where Information Becomes Intelligence. Where Discoveries Become Strategy.
GLIAG · Golden Lane Investments Advisory Group B.V.Technical Synthesis · 2026
Executive Summary
Between the January-2020 Maka Central-1 discovery and the March-2026 Roystonea-2 flow test, the Suriname deep-water margin has moved from a single-well curiosity to a producing province with a sanctioned 220,000 barrel-per-day GranMorgu development and a commercial gas leg at Sloanea-1.
This synthesis compiles the nineteen wells that carry publicly-disclosed reservoir or flow-test data across Blocks 58, 52 and 53 into a single reservoir-engineering view: net-pay, porosity, permeability, API gravity, gas-to-oil ratio and — where operators disclosed them — surface flow rates.
Three findings anchor this document. First, the Campanian and Santonian turbidite systems that produce along the Stabroek trend continue essentially without stratigraphic reorganisation across the maritime boundary — Kwaskwasi-1’s 278 m of combined net-pay remains the largest Cretaceous stack disclosed on either side. Second, fluid quality follows depth and age with the predictability of a maturing basin: black oil in the Maastrichtian and Campano-Maastrichtian at 25–34° API, light oil in the middle Campanian at 35–38° API, and condensate–volatile oil in the Santonian at 38–50° API. Third, the appraisal flow rates that anchor commercial narratives — 4,800 bopd at Sapakara South-1, up to 4,800 bopd at Krabdagu-1, roughly 6,800 bopd at Kwaskwasi-1 under a restricted choke — sit inside the same 3,000–7,000 bopd envelope now typical of a modern Guyana appraisal well.
Two cautions travel with every number in this document. Operators disclose selectively, so pooled averages under-represent the heaviest and lightest tails. Restricted-rate flow tests reflect equipment choices, not physical maxima — the Kwaskwasi flow rate in particular was constrained by surface kit rather than reservoir deliverability.
“The Cretaceous fairway does not stop at the border. What stops is disclosure — and, until the Block 58 FID, sanctioned development.”
— GLIAG Technical Synthesis, July 2026
1 · Well Inventory and Disclosed Reservoir Parameters
The table below aggregates the public reservoir parameters for the nineteen wells drilled on the Suriname-side Blocks 58, 52 and 53 since 2019. Values are drawn only from operator press releases, Staatsolie communiqués and independent trade press; a dash indicates the operator has not disclosed the parameter. Where a well tested two intervals, both are shown as separate rows.
| Well | Blk | Yr | Zone | Net pay (m) | API (°) | k (mD) | Poro (%) | GOR | DST (bopd) | Outcome |
| Maka Central-1 | 58 | 2019 | Camp+Sant | 50+73 | 50/40 | — | 22 | — | — | Discovery |
| Sapakara West-1 | 58 | 2020 | Camp+Sant | 43+36 | 37/42 | — | 22 | — | — | Discovery |
| Kwaskwasi-1 | 58 | 2020 | Camp+Sant | 149+129 | 38/38 | — | 22 | — | ~6,800* | Discovery (record pay) |
| Keskesi East-1 | 58 | 2021 | Camp+Sant | 58+5 | — | — | 20 | — | — | Discovery |
| Bonboni-1 | 58 | 2021 | Maastr. | 16 | 25 | — | — | — | — | P&A |
| Sapakara South-1 | 58 | 2021 | Camp-Maastr. | 30 | 34 | 1,400 | 25 | 1,100 | 4,800 | GranMorgu anchor |
| Sapakara South-2 | 58 | 2023 | Camp-Maastr. | 36 | 34 | 1,400 | 25 | 1,100 | — | Appraisal DST |
| Krabdagu-1 U-Camp. | 58 | 2022 | Upper Camp. | 32 | 35 | 450 | 23 | 2,150 | — | Successful DST |
| Krabdagu-1 L-Camp. | 58 | 2022 | Lower Camp. | 32 | 37 | 70 | 20 | 2,650 | — | Successful DST |
| Sloanea-1 | 52 | 2020 | Campanian | — | — | — | — | — | — | Gas discovery |
| Sloanea-2 (appr.) | 52 | 2024 | Campanian | — | — | — | — | — | — | Commercial (Nov 2025) |
| Roystonea-1 | 52 | 2023 | Campanian | — | — | — | — | — | — | Oil discovery |
| Roystonea-2 | 52 | 2026 | Campanian | — | — | — | — | — | — | DST · strong oil |
| Fusaea-1 | 52 | 2024 | Campanian | — | — | — | — | — | — | Oil+gas discovery |
| Caiman-1 | 52 | 2026 | Cret. SS | — | — | — | — | — | — | Discovery |
| SAC-1 | 52 | 2026 | Campanian | — | — | — | — | — | — | DST · strong gas |
| Baja-1 | 53 | 2022 | Campanian | 34 | 38 | — | 20 | 1,900 | — | Discovery (no DST) |
| Rasper-1 | 53 | 2022 | Camp/Sant | 0 | — | — | — | — | — | Water — P&A |
Table 1 · Public reservoir/flow-test parameters, Suriname Blocks 58, 52, 53. Camp = Campanian, Sant = Santonian, Maastr. = Maastrichtian, Camp-Maastr. = Campano-Maastrichtian. * Kwaskwasi rate was operator-restricted by surface equipment.
2 · Reservoir Quality — Porosity and Permeability
Two Block 58 discoveries dominate the porosity–permeability envelope. Sapakara South-1 and Sapakara South-2 combine 25% porosity with 1,400 mD permeability in Campano-Maastrichtian turbidites — that pairing is the single most important reason these two wells anchor the sanctioned GranMorgu development rather than the volumetrically larger Kwaskwasi discovery. Krabdagu-1’s upper Campanian interval sits at roughly 23% porosity and 450 mD, still an excellent clastic reservoir; its lower Campanian interval is tighter at 20% and 70 mD but still commercially productive.
Maka Central, Kwaskwasi and Keskesi East span 20–22% porosity with permeabilities the operator has not published — a gap consistent with early-appraisal reticence rather than poor quality, given that all three wells returned flow.
The absence of Petronas well-level data on Block 52 is one of the largest limitations of any Suriname-basin synthesis today. Petronas has confirmed six discoveries on the block, including the sanctioned Sloanea-1 gas leg and successful DSTs at Roystonea-2 and SAC-1, but has released only resource-scale figures — approaching 500 MMboe recoverable in Rystad’s July 2025 estimate — not the well-level porosity, permeability or flow-rate data that would allow benchmarking against Block 58. Any Block 52 reservoir metric in this document should be read as a placeholder pending disclosure.
3 · Fluid Distribution — API Gravity and GOR
The Suriname fluid column reads like a textbook migration history. At the top of the reservoir column, Bonboni-1’s Maastrichtian oil is 25° API — heavy enough that the operator deemed the areal extent insufficient to justify tie-back. One step down, both Sapakara South wells produced 34° API Campano-Maastrichtian black oil with 1,100 scf/bbl GOR — the anchor fluid of the GranMorgu FPSO.
In the middle Campanian, Krabdagu-1 tested 35° API from its upper interval at 2,150 scf/bbl GOR and 37° API from its lower interval at 2,650 scf/bbl GOR — the classic light-oil-with-associated-gas assemblage seen along the entire Stabroek trend. Deeper still, Kwaskwasi and Maka Central hosted volatile oil and condensate as light as 42–50° API in Santonian and lower Campanian sands.
Fluid regime by well
| Well | API Gravity | GOR |
| Sapakara S-1 / S-2 | 34° API | 1,100 scf/bbl |
| Krabdagu-1 (Upper Camp.) | 35° API | 2,150 scf/bbl |
| Krabdagu-1 (Lower Camp.) | 37° API | 2,650 scf/bbl |
| Baja-1 | 38° API | 1,900 scf/bbl |
Figure 3 (tabulated) · Gas-to-oil ratio versus API gravity for the four wells with disclosed GOR. The linear GOR–API relationship places all four wells in a single, thermally-continuous fluid family.
Two facts about the fluid system carry direct commercial consequence. First, the GOR–API linearity tells us the Cretaceous reservoirs of Block 58 are being charged from a single, thermally-continuous source kitchen — most probably the upper-Cretaceous Canje Formation source that the Guyana operators identify. That means gas handling design at the GranMorgu FPSO — sized for roughly 1,100 scf/bbl at Sapakara South — will need re-checking if the Krabdagu 2,100–2,650 scf/bbl streams are tied in later.
Second, the 34° API of the sanctioned anchor fluid places GranMorgu’s crude at a lower discount to benchmark than the Guyana Liza stream (32° API) but requires no exotic handling. From an offtake perspective, this is a well-behaved crude.
4 · Net-Pay Distribution
The net-pay ranking of the Block 58 portfolio is stable and well-understood: Kwaskwasi-1 at 278 m combined (149 m Campanian, 129 m Santonian), Maka Central-1 at 123 m combined (50 m Campanian, 73 m Santonian), Sapakara West-1 at 79 m (43+36), Keskesi East-1 at 63 m (58+5). The GranMorgu anchor wells — Sapakara South-1 and -2 — hold 30–36 m each of Campano-Maastrichtian pay, and Krabdagu-1 holds 32 m in each of two stacked Campanian intervals.
The commercial reading is important: Kwaskwasi’s headline pay dwarfs the other wells, but its Santonian condensate leg contributed to the decision not to anchor GranMorgu on it. Development selection has been driven by fluid quality and reservoir permeability, not by pay thickness in isolation.
5 · Productivity — DST Flow Rates and Forward View
Only three Block 58 wells carry publicly-disclosed surface flow rates. Sapakara South-1 flowed 4,800 bopd at 1,100 scf/bbl GOR; Krabdagu-1 flowed at rates the operator described as commercial from both Campanian intervals; and Kwaskwasi-1 tested at roughly 6,800 bopd on a restricted choke, with TotalEnergies noting the rate reflected an engineering constraint on the test equipment rather than a reservoir maximum. None of the Block 52 or Block 53 wells have flow rates in the public domain, though Petronas and Staatsolie both describe Roystonea-2 and SAC-1 as having demonstrated strong oil and gas deliverability respectively. Baja-1 was completed as a discovery on log evidence alone and never flow-tested before APA relinquished the remainder of Block 53.
The forward view is dominated by two milestones. First, the October 2024 GranMorgu FID commits TotalEnergies and APA to a 220,000 bopd FPSO for first oil in 2028; this locks in Sapakara South and Krabdagu as the anchor fields and defers Kwaskwasi to a possible later tie-back subject to fluid-handling studies. Second, Petronas’s Sloanea-1 commerciality declaration in November 2025 opens a parallel gas-development track — whether via FLNG or a pipeline route to shore is not yet public. Together, these two projects give the Suriname side of the basin its first firm production trajectory since Frontera’s much smaller Corentyne Maastrichtian development on the Guyana side.
6 · Method, Sources and Limitations
Sources
Every number in this document is drawn from an operator press release, a national-oil-company communiqué, or a named trade publication. Where two sources disagree on the same parameter, the operator’s own disclosure was preferred. No proprietary reservoir simulation, seismic reinterpretation, well-log data or internal engineering estimate has been used. GLIAG has not had sight of any Staatsolie, TotalEnergies, APA or Petronas confidential material in preparing this note.
Method
The dataset was assembled from public disclosures well-by-well, then normalised to consistent units (metres for pay, degrees API for gravity, scf/bbl for GOR, millidarcies for permeability, percent for porosity, barrels per day for flow rate). Where an operator quoted a range, the mid-point is tabulated. Rates reported as restricted or choked are flagged as such to avoid over-reading a surface constraint as a reservoir maximum.
Limitations
Three limitations apply throughout. First, disclosure asymmetry: APA and TotalEnergies have released well-level porosity, permeability and flow-rate data for Block 58 but Petronas has not for Block 52 — Block 52 rows in Table 1 are therefore sparse. Second, restricted-choke bias: three of the four disclosed Block 58 flow tests were run on constrained surface kit rather than at reservoir absolute open-flow potential; pooled averages therefore understate deliverability. Third, single-zone-well bias: some wells (Bonboni-1, Baja-1) were completed after a single-zone test, so the reservoir characterisation captured here is a lower bound on what those wells actually encountered.
Interpretation and Disclaimer
This synthesis is a scientific compilation of publicly available operator disclosures. It is not investment advice. It is not a resource statement made under PRMS or SEC standards. Any commercial decision derived from the contents of this document should be verified against the underlying operator disclosures, cited in full below, and — where possible — corroborated by independent reservoir-engineering review.
References
1. APA/Total, Maka Central announcement (Jan 2020) — https://www.spglobal.com/commodity-insights/en/news-research/latest-news/natural-gas/010720-apache-total-make-significant-oil-gas-find-offshore-suriname
2. APA Corporation — Sapakara flow test — https://investor.apacorp.com/news-releases/news-release-details/apa-corporation-announces-second-successful-flow-test-sapakara
3. APA Corporation — Krabdagu flow test — https://investor.apacorp.com/news-releases/news-release-details/apa-corporation-announces-successful-flow-test-results-krabdagu
4. APA Corporation — Block 53 first discovery (Baja-1) — https://investor.apacorp.com/news-releases/news-release-details/apa-corporation-announces-first-discovery-block-53-offshore
5. Offshore Magazine — Krabdagu resource — https://www.offshore-mag.com/drilling-completion/article/14278533/krabdagu-well-offshore-suriname-suggests-in-place-resource-of-180-mmbbl
6. Reuters — Rasper-1 water — https://www.reuters.com/business/energy/apas-rasper-well-suriname-strikes-water-2022-06-13/
7. Offshore-Energy — Kwaskwasi flow test — https://www.offshore-energy.biz/totalenergies-well-flow-test-off-suriname-supports-hopes-for-oil-development-hub/
8. TotalEnergies — Keskesi discovery (fourth Block 58) — https://totalenergies.com/news/news/total-announces-fourth-discovery-block-58-offshore-suriname
9. Petroleum Energy Insights — Sapakara South — https://petroleumenergyinsights.com/sapakara-south-flow-test-pioneering-surinames-oil-production/
10. Staatsolie — Block 58 FID (GranMorgu) — https://www.staatsolie.com/en/news/totalenergies-and-apa-corporation-announce-final-investment-decision-for-block-58/
11. Petronas — Block 52 hydrocarbon discovery — https://www.petronas.com/media/media-releases/petronas-makes-hydrocarbon-discovery-block-52-offshore-suriname
12. Petronas — Block 52 three new successes — https://www.petronas.com/media/media-releases/petronas-records-three-new-successes-surinames-block-52-bringing-total
13. Rystad Energy — Block 52 500 MMboe estimate — https://www.rystadenergy.com/insights/petronas-closing-in-on-500-million-boe-at-block-52-offshore-suriname
14. Offshore Magazine — Petronas FLNG option — https://www.offshore-mag.com/regional-reports/latin-america/article/55135021/petronas-exploration-success-offshore-suriname-leads-petronas-to-consider-flng-option
15. Staatsolie — Sloanea-1 commercial approval — https://www.staatsolie.com/en/news/staatsolie-approves-commercial-field-for-sloanea-1-gas-discovery-in-block-52/
16. GEO ExPro — Guyana–Suriname connection — https://geoexpro.com/the-guyana-suriname-connection/
17. GEO ExPro — Suriname exploration perseverance — https://geoexpro.com/hydrocarbon-exploration-suriname-perseverance-rewarded/
18. Oil Price — Suriname oil dream drilling data — https://oilprice.com/Energy/Crude-Oil/New-Drilling-Data-Reignites-Surinames-Oil-Dream.html
19. Offshore Industry — Stabroek FPSO path to 1.5 mmbpd — https://offshoreindustry.co.uk/guyana-stabroek-block-exxonmobils-seventh-fpso-and-the-path-to-1-5-million-bpd/
20. OGJ — APA Baja area / Block 53 vacate — https://www.ogj.com/general-interest/article/14306038/apa-to-continue-baja-area-exploration-offshore-suriname-vacates-remainder-of-block-53
21. OGJ — Frontera Corentyne Maastrichtian — https://www.ogj.com/exploration-development/area-drilling/article/14302623/frontera-energy-to-develop-maastricht-layers-in-corentyne-block
Prepared by GLIAG — Golden Lane Investments Advisory Group B.V., Delft, The Netherlands. Content is © GLIAG 2026 and may be quoted with attribution. Data cited from the referenced third-party sources remains the intellectual property of those parties.
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