Carbonates in the Petroleum Industry

Nomenclature and fundamental depositional environments

• Carbonate grains and classifications
• Lacustrine carbonates
• Carbonate ramps and platforms
• Modern carbonate depositional environments
• Arabian Gulf
• Caribbean

Lacustrine carbonates are topical in view of the major petroleum discoveries of the South Atlantic. Emphasis is also placed on the contrast between modern arid and humid depositional settings of shallow water marine carbonates by comparing those of Abu Dhabi and the Caicos Islands respectively.

Carbonate facies in more detail

• Salinas
• Grainstone environments
• Aeolian activity in arid climates
• Microbialites and algae
• Reefs
• Chalks
• Bioturbation
• Re-sedimented carbonates
• Carbonate source rocks

The session concentrates even deeper on primary carbonate sediments including their associated windblown deposits, associated evaporitic environments, deeper water mass flow carbonates and source potentials. Microbialites are addressed with reference again to the South Atlantic discoveries.

Diagenesis and reservoir characterisation

• Diagenetic alterations
• Dissolution / karstification
• Cementation
• Replacement
• Neomorphism
• Compaction
• Reservoir characterization
• Petrophysics
• Seismic
• 3D modelling (deterministic and stochastic)
• Saturation modelling
• Fracture modelling
• Quantifying volumetric uncertainty
• Flow units

Chemical and physical alterations to carbonates at the surface and during burial are addressed with particular attention paid to the effects of meteoric leaching and dolomitisation. 3D attribute and 3D fracture modelling techniques are discussed with emphasis on geological uncertainty and reservoir drainage issues.

 Sequence stratigraphy and case studies

• Sequence stratigraphy
• Ancient carbonate sequences
• Devonian, Western Canada
• Lower Carboniferous ramp and platform carbonates, UK
• Triassic Dolomites, Italian Alps
• Mexican Cretaceous Golden Lane and Poza Rica trends; Cantarell Field
• Middle East plays (Khuff, Arab, Thamama, Shuaiba, Mishrif, Simsima)

Stratigraphic architectures are examined through sequence stratigraphy. Much of the session is devoted to understanding carbonate depositional models based on excellent outcrops often at the seismic scale. Contrasting carbonate successions of various parts of the Caribbean, North America, the UK and mainland Europe are covered together with several carbonate reservoir plays in the Arabian/Persian Gulf area.

 Miocene Case studies

• Southern Spain (reefs of Sorbas-Nijar Basins)
• Balearic Islands (Majorca reef; Menorca outer ramp processes)
• Sardinia syn-rift carbonates
• Malta (carbonate oozes, biostromes, phosphorites and extreme karstification)
• Gulf of Suez synrift carbonates
• Far East fields

Particular attention is paid to the highly varied Miocene carbonates at various localities in and around the Mediterranean Sea and to numerous fields in the Far East including: Indonesia, Malaysia, Sarawak, Philippines, China and Viet Nam.