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Scope of Work
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SCOPE OF WORK
The Contractor shall carry out the services of core analysis with the best international practice.
1 Wellsite service and/or Company’s Warehouse in Iraq
The wellsite service and/or from Company’s Warehouse in Iraq should include, but not limited to the following:
1.1 Supervision of wellsite coring operation and mud logging crew to recover the core from the wells and box the cores in accordance with industry standard and the instruction of Company.
1.2 To cut the full diameter core with the seal mandrel when core Pull Out Of Hole (POOH) as per the Company instruction.
1.3 Wellsite and/or Company’s Warehouse core handling, such as: core labeling or marking, core gamma (if applicable).
1.4 Document preparation and Transportation of core sample from the Halfaya Camp to Contractor's lab and from lab to Halfaya Camp.
1.5 The contractor shall provide all equipment and consumables used during the wellsite service and/or Company’s Warehouse period, including its transportation to and from the aforementioned service site.
2 Preparation of core plugs and fluids to be used in core analysis
2.1 Preparation of core plugs
(a) Core gamma: including core layout, marking, orientation and depth adjustment together with wireline logs.
(b) Core slabbing: including longitude cutting and brief lithological description, core preservation for half of the cores after slabbing.
(c) Drilling and trimming standard plugs: including drilling the standard plug with specific brine or oil, trimming the surface and labelling of all the plugs.
(d) Drilling and trimming full diameter plugs: including drilling the oversize full diameter plugs, lathing as full diameter plugs as requirements, ends trimming and labelling.
2.2 Preparation of fluids to be used in core analysis
(a) Synthesis of brine: including the density and viscosity (kinematic) measurement.
(b) Crude oil preparation: including filtration, degassing, de-watering, separation of sediments and heavy crude oil, density and viscosity measurements.
2.3 Photographing (under white and UV light) before core plugging and after slabbing, etc. (preferred to be conducted at Company's Core Warehouse).
2.4 Detailed core description, including lithology, structure, hydrocarbon showing depositional environment.
3 Conventional core analysis
The performance of the conventional core analysis that may include, but not limited to the following:
3.1 Source Rock Geochemistry
(a) Rock-Eval Pyrolysis
(b) Total organic carbon analysis by leco analysis
(c) Carbon, Sr, sulfuer and other isotope tests indicating the age and environment of sedimentation
(d) Vitrinite reflectance (Ro)
(e) Organic matter type experiment (kerogen elemental analysis and micro component analysis)
3.2 CT-scanning and core photography
(a) CT-scanning for standard plugs and full diameter plugs
(b) Core photography with white and ultraviolet light for standard plugs and full diameter plugs
3.3 Porosity, permeability and grain density measurements
(a) Residual fluids saturation and porosity by summation of fluids with Dean-Stark method for standard plugs and full diameter plugs
(b) Porosity measurements: including ambient conditions and reservoir conditions for standard plugs and full diameter plugs
(c) Permeability to air measurements: including ambient conditions and reservoir conditions for standard plugs and full diameter plugs, especially vertical and horizontal permeability for full diameter plugs
(d) Permeability with Klinkenberg calibration
(e) Grain density measurements: including standard plugs and full diameter plugs
(f) Combined analysis for porosity, permeability and grain density measured as above mentioned, including for ambient condition and reservoir condition, for standard plugs and full diameter plugs
3.4 Core description: detailed core description based on above data, including lithology, sedimentary, deposition environment, diagenetic textures, pore types, textures and oil stain, etc.
3.5 Rock properties
(a) XRD (X-ray Diffraction) whole rock and clay (<2 microns)
(b) Thin section with description
(c) SEM (Scanning Electron Microscope) section with description
(d) Co and Cw at ambient condition
3.6 Electricity parameters
(a) Formation resistivity factor (“m” and “a” value), including ambient condition and different overburden pressure, reservoir condition
(b) Extracted water resistivity factor at ambient condition
3.7 Wettability restoration and wettability (Amott/USBM), including the wettability restoration at reservoir condition and wettability measurements at ambient condition.
3.8 Any other conventional analyses as required by PetroChina
4 Special core analysis
The performance of the Special core analysis that may include, but not limited to the following:
4.1 Capillary pressure curve
(a) Air-Mercury injection capillary pressure tests (drainage and imbibition)
(b) Air-brine and oil-brine capillary pressure tests (drainage and imbibition) by porous-plate and/or centrifuge method
(c) Pore entry radius distribution
(d) Disposal of mercury contaminated samples
4.2 End point test: including centrifuge method under ambient condition and overburden pressure
4.3 Geomechanics parameter
(a) Triaxial Young’s, Poisson’s and compressive strength at reservoir temperature
(b) Ultrasonic velocity teste at reservoir stress condition
(c) Hydraulic fracture design parameters, including Young's modulus, Poisson's ratio, fracture toughness, fracture gradient and ultrasonic velocities
(d) Natural fracture conductivity at five closure stresses, including fracture conductivity and closure stress analysis
(e) Brazil tensile strength tests
(f) Biot's coefficient determination-measured at reservoir stress condition
4.4 Relative permeability tests
(a) Water-oil curves at reservoir condition by unsteady-state method or steady-state method for standard plugs, including drainage and imbibition
(b) Oil-gas curves at reservoir condition by unsteady-state method or steady-state method for standard plugs
(c) Water-oil curves at reservoir condition by steady-state method for full diameter plugs, including drainage and imbibition
4.5 Residual gas determination
4.6 Formation sensitivity analyses, including water sensitivity, salinity sensitivity, velocity sensitivity, acid sensitivity and alkali sensitivity.
4.7 NMR measurements, including T1 and T2 measurements
4.8 Staggered-Plugs measurements: including depletion test, water displacement and gas displacement under reservoir condition.
4.9 Any other special analyses as needed by Company
5 Package and transportation
5.1 Preparation of the documents for anything in and out of Iraq by shipment
5.2 Core package, including box preparation, package the cores and core plugs
5.3 Shipments:
5.3.1 The cores and core plugs from wellsite/Company warehouse to contractor’s lab shipment
5.3.2 The cores and core plugs from contractor’s lab return to Company warehouse HFY Iraq shipment .
6 Deliverable Requirement and Data Transmission
6.1 Contractor shall deliver Final report with 2 hard copies and 2 soft copies in English language and indicate the industry standard that has been adhered in.
6.2 Besides graphs and figures, Contractor shall provide raw test data as well as calculated results in the digital format with formula so that Company can easily alter the calculation with updated or more representative parameters that are different from what Contractor has used or assumed in its original calculation.
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