GUIDE TO WORLD CRUDES: StatoilHydro publishes Gimboa crude oil assay

April 6, 2009
StatoilHydro has published a crude oil assay for its Gimboa field, which began producing first-quarter 2009 from Block 4/05 about 3 miles off Angola (Fig. 1) in 2,300 ft of water.

StatoilHydro has published a crude oil assay for its Gimboa field, which began producing first-quarter 2009 from Block 4/05 about 3 miles off Angola (Fig. 1) in 2,300 ft of water.

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Production is from two different reservoirs with expected gravity at 23° API, according to the published report.

Sonogol operates the field on behalf of Statoil-Hydro ACR (Angola Consulting Resources) and SOMOIL (Sociedade Petrolefira Angolana). Estimated recoverable reserves are about 50 million boe.1

The Gimboa project consists of three production and four water-injection subsea wells around a central manifold. That manifold is tied back to a floating production, storage, and offloading (FPSO) unit.

Working under a $570 million contract, Saipem last year delivered the FPSO Gimboa, a converted oil tanker with 1.8 million bbl of oil storage. It has production capacity of 60,000 b/d of oil and 60,000 b/d of water. Maximum natural gas production is 36.8 MMcfd.

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Fig. 2 shows a true boiling point (TBP) curve for the whole crude.

The following data are from StatoilHydro.

Whole crude

Density at 15° C., kg/l.: 0.9114
Specific gravity: 0.9119
API gravity, °API: 23.67
Sulfur, mass %: 0.646
Total acid number, mg KOH/g: 0.78
Pour point, °C.: –33
Kinematic viscosity at 20° C., cst/sec: 92.25
Kinematic viscosity at 50° C., cst/sec: 23.38
Nitrogen, mg/kg: 2,367
Vanadium, mg/kg: 37
Nickel, mg/kg: 29.0
Sodium, mg/kg: 1.0
Salt as NaCl, mg/l.: 29.0
Wax content, mass %: 1.2
Water content, vol %: <0.025

Pentanes to 165° C.

Yield, mass %: 5.73
Yield, vol %: 6.75
Density at 15° C., kg/l.: 0.7742
Sulfur, mass %: 0.0337

165-250° C.

Yield, mass %: 14.86
Yield, vol %: 16.2
Density at 15° C., kg/l.: 0.8359
Sulfur, mass %: 0.0819

250-335° C.

Yield, mass %: 18.54
Yield, vol %: 19.51
Density at 15° C., kg/l.: 0.8660
Sulfur, mass %: 0.244

335-525° C.

Yield, mass %: 30.63
Yield, vol %: 30.10
Density at 15° C., kg/l.: 0.9273
Density at 70° C., kg/l.: 0.8890
Kinematic viscosity at 80° C., cst/sec: 14.82
Kinematic viscosity at 100° C., cst/sec: 8.337
Sulfur, mass %: 0.658

525-565° C.

Yield, mass %: 7.94
Yield, vol %: 7.60
Density at 15° C., kg/l.: 0.9527
Density at 70° C., kg/l.: 0.9147
Kinematic viscosity at 80° C., cst/sec: 73.76
Kinematic viscosity at 100° C., cst/sec: 32.37
Sulfur, mass %: 1.07

Reference

  1. www.offshore-technology.com; SPG Media Ltd.