Operations Integrity Management System Document Tittle: Geology & Reservoir Module Document Code : OS-HPST- D004 Issue No: 01 Revision No: 01 Revision Date: 20st Oct 2015 Weathering and erosion Deposition in oceans and on continents Uplift Sediments Increasing temperature and pressure Uplift Igneous rocks Heat & pressure Uplift Burial and lithification Sedimentary rocks Heat & pressure Metamorphic rocks Cooling Melting Magma Geology & Reservoir Prepared by: Husam Helou Rev No: 01 Reviewed by: Suriya Lertpun th Issued date: 15 Oct 2015 Approved by: Martin McCaffrey Controlled copy online Private & Confidential Page 1 of 1 1 GEOLOGY Private & Confidential • The science which concerns the history of the earth and it's life, especially as recorded in the rocks. – GEO - Greek for "earth" – LOGIS - Greek for "study" • Why is Geology so important to the Reservoir Engineer? Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 2 Earth Model Solid Iron Inner core (5150 - 6370 km) Private & Confidential Liquid Iron Outer core (2891 - 5150 km) Mantle (40 - 2891 km) Crust (0 - 40 km) • Homogeneous • Layered structure Prepared by: Husam Helou 3 Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 3 Basic Concepts Private & Confidential • The earth was formed some 4 to 5 billion years ago. • As the earth cooled, Igneous Rocks were formed. • Rock Cycle begins due to erosion. • Sedimentary Basins form. • Accumulation of Algae, Marine Animals and Plants occurs in Source Rocks. • Tectonics --> Temperature --> Time = Hydrocarbons Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 4 4 Rock cycle Private & Confidential Weathering and erosion Deposition in oceans and on continents Uplift Sediments Increasing temperature and pressure Uplift Igneous rocks Heat & pressure Uplift Burial and lithification Sedimentary rocks Heat & pressure Metamorphic rocks Cooling Melting Magma Prepared by: Husam Helou 5 Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 5 Rock-forming Source of process material Classification of rocks Private & Confidential IGNEOUS SEDIMENTARY METAMORPHIC Melting of rocks in hot, deep crust and upper mantle Weathering and erosion of rocks exposed at surface Rocks under high temperatures and pressures in deep crust Crystallization (Solidification of melt) Sedimentation, burial and lithification Recrystallization in solid state of new minerals Prepared by: Husam Helou 6 Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 6 Igneous rocks Private & Confidential Basalt Gabbro Examples Rhyolite Granite Prepared by: Husam Helou 7 Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 7 Metamorphic rocks Examples Private & Confidential Gneiss Mica schist Slate Marble Quartzite Prepared by: Husam Helou 8 Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 8 Sedimentary Rocks Private & Confidential The third category is Sedimentary rocks. These are the most important for the oil industry as it contains most of the source rocks and cap rocks and virtually all reservoirs. Sedimentary rocks come from the debris of older rocks and are split into two categories: • Clastic rocks - formed from the materials of older rocks by the actions of erosion, transportation and deposition. • Non-clastic rocks - from chemical or biological origin and then deposition. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 9 Clastic sedimentary rocks Private & Confidential Conglomerate Breccia Examples Shale Sandstone Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 10 Clastic Rocks Private & Confidential •Clastic rocks are sands, silts and shales. The difference is in the size of the grains. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 11 Carbonates Private & Confidential Carbonates form a large proportion of all sedimentary rocks. They consist of: – Limestone. – Dolomite. Carbonates usually have an irregular structure. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 12 Carbonate types Private & Confidential • Limestone CaCO3 • Dolomite CaMg(CO3)2 . Dolomite is formed by the replacement of some of the calcium by a lesser volume of magnesium in limestone by magnesium. Magnesium is smaller than calcium, hence the matrix becomes smaller and more porosity is created. • Chalk is a special form of limestone and is formed from the skeletons of small creatures (cocoliths). Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 13 Sedimentation & rock record Private & Confidential Increasing age of rocks Sedimentation in lake or sea Sedimentary rocks • Relative ages of rocks Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 14 Geologic Time Scale 0 0.01 1.6 5.3 24 37 57 66 Epoch Period Recent Pleistocene Pliocene Miocene Oligocene Eocene Paleocene Quaternary Tertiary Era Private & Confidential Eon Cenozoic Phanerozoic 144 208 245 286 360 408 438 505 570 Cretaceous Jurassic Triassic Permian Carboniferous Devonian Ordovician Silurian Cambrian Mesozoic Paleozoic Proterozoic Prepared by: Husam Helou 15 Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 15 Earth Crust Movements Private & Confidential - Tectonic stresses - Faults - Folds Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 16 16 Crustal Plates • Plate boundaries • Relative velocities (cm/yr) Private & Confidential • Continental crust • Oceanic crust Prepared by: Husam Helou 17 Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 17 Rock Deformation Private & Confidential Crustal movement causes 2 types of surface deformation Folding Faulting Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 18 Deformational Features COMPRESSIVE FEATURES Folding Inverse Fault TENSIONAL FEATURES Private & Confidential SHEARING FEATURES Stretching and thinning Shearing Normal Fault Lateral Fault Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 19 Faults & Folds Private & Confidential 900 m Example Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 20 Folding Private & Confidential Example Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 21 Fold Terminology Private & Confidential Anticline Syncline Youngest rock Oldest rock Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 23 Fold Terminology Symmetrical folds Asymmetrical folds Private & Confidential Overturned folds Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 24 Anticline Private & Confidential Anza-Borrego, California Example Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 25 Overturned Folds Private & Confidential Example Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 26 Faulting (normal faults) Private & Confidential Example Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 27 Types of Faults BEFORE FAULTING Normal fault Private & Confidential Fault plane Ex ten si o n Reverse fault Sh ort en ing DIP-SLIP FAULTS Left-lateral fault STRIKE-SLIP FAULT OBLIQUE-SLIP FAULT Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 28 Sedimentation Private & Confidential Environment for Sedimentary Rocks accumulation Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 29 Sedimentation 1 Private & Confidential • Sediments settle to the bottom of the sedimentary basin. • As the sediments accumulate the temperature and pressure increase expelling water from the sediments. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 30 Sedimentation 2 Private & Confidential • Sedimentary muds become sedimentary rocks. • Calcareous muds become limestone. • Sands become sandstone. Another effect involves both the grains in the matrix and the fluids reacting to create new minerals changing the matrix and porosity. Fluids can also change creating a new set of minerals. This whole process is called Diagenesis. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 31 Particle Size Classification Sediment Coarse Gravel Particle size (mm) Private & Confidential Rock boulder 256 Conglomerate cobble 64 pebble 2 Sandstone Sand 0.062 Siltstone Mud Silt 0.0039 Clay Fine Mudstone Shale Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 32 Depositional Environments Private & Confidential • The depositional environment can be • Shallow or deep water. • Marine (sea) and lake or continental. • This environment determines many of the reservoir characteristics Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 33 Depositional Environments 2 Private & Confidential • Continental deposits are usually dunes. • A shallow marines environment has a lot of turbulence hence varied grain sizes. It can also have carbonate and evaporite formation. • A deep marine environment produces fine sediments. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 34 Depositional Environments 3 Private & Confidential • The depositional characteristics of the rocks lead to some of their properties and that of the reservoir itself. • The reservoir rock type clastic or non-clastic. • The type of porosity (especially in carbonates) is determined by the environment plus subsequent events. • The structure of a reservoir can also be determined by deposition; a river, a delta, a reef and so on. • This can also lead to permeability and producibility. of these properties are often changed by further events. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 35 Depositional Environment 4 Private & Confidential • The environment is not static. • Folding and faulting change the structure. • Dissolution and fracturing can change the permeability. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 36 Sedimentary Rock Types Private & Confidential Sandstone and conglomerate 11% Limestone and dolomite 14% • Relative abundance Siltstone, mud and shale 75% Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 37 Depositional Environment Carbonates Private & Confidential Carbonates are formed in shallow seas containing features such as: • Reefs. • Lagoons. • Shore-bars. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 38 Hydrocarbons Origination Private & Confidential • Hydrocarbon Origination – Organic – Inorganic Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 39 Hydrocarbon Accumulation Private & Confidential • Five Factors Necessary: 1.Mature Source Rock 2.Migration Pathway 3.Reservoir Rock 4.Trap 5.Seal Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 40 Source Rock Private & Confidential • Accumulation of Organic Matter • Preservation of Organic Matter • Thermal Maturity – – • • • • Subsurface heat "Oil Window" Shale ~ 65% Marl ~ 12% Carbonate ~ 21% Coal ~ 2% Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 41 Hydrocarbon Migration Private & Confidential Hydrocarbon migration takes place in two stages: • Primary migration - from the source rock to a porous rock. – This is a complex process and not fully understood. – It is probably limited to a few hundred metres. • Secondary migration - along the porous rock to the trap. – This occurs by buoyancy, capillary pressure and hydrodynamics through a continuous water-filled pore system. – It can take place over large distances. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 42 The Trap Private & Confidential • A geometric configuration of structures and/or strata, in which permeable rock types (the reservoir) are surrounded and confined by impermeable rock types. • Structural Traps: • Anticlines • Faults • Salt Diapers (Domes) • Stratigraphic Traps: • • • • Salt Diapers (Domes) Uncomformities Reefs Others • Combination Traps Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 43 Dome Structure Private & Confidential Dome Structure Oil and gas migrate upward from source beds until trapped by the impermeable cap rock Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 44 Salt Dome Trap Private & Confidential Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 45 Trap Formed by a Fault Private & Confidential Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 46 Unconformity Trap Private & Confidential Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 47 Change in Formation Properties Private & Confidential Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 48 Types of Traps Private & Confidential Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 49 The Seal Private & Confidential • Impermeable Barriers • Caprocks • Types of Seals – Shale ~ 65% – Evaporites (Salt) ~ 33% – Carbonates ~ 2% Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 50 Reservoir Structure • • • Private & Confidential There are many other types of structure. The criteria for a structure is that it must have: – Closure, i.e. the fluids are unable to escape. – Be large enough to be economical. The exact form of the reservoir depends on the depositional environment and post depositional events such as foldings and faulting. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 51 Reservoir Mapping Private & Confidential • Reservoir contours are usually measured to be below Mean Sea Level (MSL). • They can represent either the reservoir formation structure or fluid layers. Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 52 The Reservoir Private & Confidential Four Required Basic Fundamentals • Porosity: – Void space • Permeability: – Ability for fluid to flow through rock • Pressure • Petroleum (Hydrocarbon Saturation) Most Common Reservoir Rocks • Sandstone's ~ 60% • Carbonates ~ 39% Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 53 QUIZ Private & Confidential 1- Mention the main 3 types of rock ? A: Igneous, Sedimentary, Metamorphic 2- What is the main type of rock for reservoirs ? A: Sedimentary: Sandstone & Carbonate 3- What are the main types of Carbonate rock ? A: LimeStone, Dolomite, Chalk 4- What are the main condition to have a reservoir A: Porosity, Permeability, Pressure, Petroleum Prepared by: Husam Helou Reviewed by: Suriya Lertpun Approved by: Martin McCaffrey Rev No: 01 Issued date: 15th Oct 2015 Controlled copy online 54
