Prospectus re Admission to the Official List - Heritage Oil

RPS EnergyHeritage Oil – Competent Persons ReportA summary of input rock and fluid properties is given in Table 12.Low Mid HighMishrif/MauddudGRV ............................................. MM m 3 1,671 3,844 4,023N:G.............................................. % 1 1 1Porosity-Mish-Maudd ................................. % 1.3 1.7 2.1Porosity- Mish 2&3 ................................... % 1.7 2.85 4.0Sw............................................... % 50 33 18.51/FVF ............................................ stb/rb 0.392 0.370 0.351ThamamaGRV ............................................. MM m 3 559 1,091 1,622N:G.............................................. 1 1 1Porosity ........................................... % 1.6 2.3 3.0Sw............................................... % 50 40 301/FVF ............................................ stb/rb 0.488 0.455 0.426Table 12:West Bukha Volumetric Input ParametersIn-place volumes were calculated probabilistically for the Mishrif/Mauddud and Thamama reservoirs forboth the whole field and for the portion of the field in Omani waters.Whole Field (MMstb) Omani Waters (MMstb)Reservoir p90 p50 p10 p90 p50 p10Mishrif/Mauddud ............................. 168.0 242.0 331.0 53.6 82.9 119.0Thamama ................................... 54.5 88.5 136 24.8 41.2 62.7Total ................................... 252.0 335.0 434.0 91.2 126.0 267.0N.B.The totals are the p90, p50 and p10 of the stochastically consolidated distributions.Table 13:West Bukha In place Volumes 100 per cent. Basis3.3.4. Petroleum Engineering3.3.4.1. Reservoir Fluid PropertiesThere has previously been debate amongst the legacy owners of the West Bukha field as to whether thereservoir contains a rich gas (or ‘‘condensate’’) type fluid, or a volatile oil, and latterly the field ownershave come to the conclusion that the reservoir fluid is a volatile oil. Such confusion is common when thefluid is a near-critical point fluid, as liquid:gas ratios during short well tests can be misleading, andrepresentative sampling difficult. We note that the NIOC has always maintained that the field is a volatileoil field.Upon examination of the fluid samples captured in wells Henjam-1 and West Bukha-2, and the laboratoryanalyses of same, we have concluded that the fluid is more likely to be oil at reservoir conditions, for thefollowing reasons:The methane (‘‘C 1 ’’) content is below 60mol per cent.;The test separator GOR is 12 mol per cent.;The CVD experiment yielded 100 per cent. liquid saturation at the saturation pressure;A differential vaporisation experiment was performed and a bubble point measured (this would not bepossible on a gaseous fluid).The initial reservoir fluid composition is as shown in Table 3.6 overleaf. The source of this is the PVTanalysis of samples from DST 2 in the Mishrif Formation in Well West Bukha-2; the reservoir fluid in theunderlying Thamama formation is similar. Approximately 1.4 mol per cent. H 2 S has been measured in thereservoir samples, and approximately 14 mol per cent. CO 2 and N 2 .87