Presentation on theme: "Petroleum Geology and the Permian Basin Andrew McCarthy Concho Resources."— Presentation transcript:
Petroleum Geology and the Permian Basin Andrew McCarthy Concho Resources
Petroleum System 2 Source: organic-rich mudrock Heat (burial) and time Reservoir: porous rock Seal: low-permeability rock Trap
Source Sol (our sun) Fusion (of hydrogen and helium) Earth 3,850,000 exajoules per year – Solar radiation 3,000 exajoules per year – captured by plant life 500 exajoules per year – total human use (fossil, nuclear, etc.) 3,850,000 EJ 3,000 EJ burial
Source Heat and pressure Kerogen Kerogen: geo-plastic or geo-chocolate. Lipids, proteins, carbohydrates Gas (methane, ethane, propane) Texas tea (light, sweet crude) CO2 N2 H2S + Shale: high organic material
How much heat? Low temps yield nothing: <60 C High temps yield oil: 60C-120+C Higher temps yield gas: 120+C
100% natural and organic Oil is 100% natural and organic 95%++ of all oil ever generated has been naturally leaked to the surface Millions of natural oil seeps exist around the planet, many under the oceans Yummy! Natural Oil seeps (BP not Involved) Not Iced tea
An oil reservoir at the surface Oil reservoirs are exposed and eroded away. The light oil is biodegraded, tar remains.
OK. So far we have: Source Heat and time Now we need a reservoir, a seal, and maybe a trap
Reservoir The first key to a reservoir rock is porosity intergranularfracture
A very conventional petroleum system: Concho sand organic shale sealing shale oil
Organic mudstone, silty shale, with varying carbonate and silica content 1 source 2 reservoir 3 seal Tight carbonate (seal/frac barrier) Today: Unconventional plays
“Shale” plays What is shale? Silt vs. clay Mudrocks (silt, clay, organics, carbonate) Needs help: must be fracture-stimulated (poor natural permeability) Shale rocks can serve as – Source – Reservoir – Seal
Reservoirs *Just about everything! sands Shale/silt carbonates
What does a geologist do? Exploration very little data! – Seismic, basin geochem, remote sensing – Everything changes with the first well Development increasing amounts of data! – Well logs, core, production data Operations – Day-to-day drilling When do we have “the answer”?