Drilling and Production 6/29/16

What do we know We have covered what happens up until we drill the well Geoscience behind finding traps and reservoirs Confirm with seismic data that there is a possible trap Find the OOIP/OGIP using quantities like porosity and water saturation Now we ask how do we drill the best well?

Drilling Drilling engineering begins once a company decides that the possible reserves are worth extracting

Drill Site Housing for workers Derrick Separators Transport Truck Fracking/Drilling Fluid Storage Tanks

How to drill if it is offshore? Offshore Floating Drill Rig Offshore Drill Ship

Lets Look in closer We drill down to a high pressured reservoir and the high pressure pushes oil out of the pores and into the borehole This is called “Primary Recovery” and is how the first oil wells were productive To do this, rising oil and possible chemicals from drilling rise up thousands of feet To prevent these fluids from going back into other layers, and possible water aquifers, we protect our well with a casing Concrete layer that won’t allow flow of oil and gas into the wrong area

Casing How do we get a layer of concrete 6000ft below the surface of the earth? We drill down with a large bit, then put in a smaller inner tube, then fill the void space with concrete We do several steps of this getting smaller and smaller until we get to our target zone This casing is what keeps us from leaking possible chemicals into other rocks, isolating contact between reservoir and surface

Casing

How do we know how big? Wee look at the flow rate that we are expecting to see, and the pressures that the fluids will be Have to calculate the exact best diameter and thickness of pipe that we want to put from very top to the bottom

What do we do after we drill? Primary Production Let the big pressure difference bewteen the reservoir and the surface “push” the fluid up Secondary Production If the pressure differential is not as big as we want, we can increase it by pulling up and pumping Think of it like using a straw to bring liquids out of a cup

Pumping Methods There are several pumping methods, but the most common is Rod Pumping, seen below… and here...

After Secondary Production If we still are not getting out what we want from secondary production, in pumping, we can move to tertiary production methods There are hundreds of tertiary production methods (EOR) Enhanced Oil Recovery Hydraulic Fracturing (Fracking) Water/Gas Flooding Polymer Flooding Surfactant Flooding (What I do!) Plasma Pulse Fire Flooding Cryogenic Fracturing

Hydraulic Fracturing Hydraulic Fracturing is when we pump water and chemicals into our reservoir, to cause such high pressure that the reservoir rock will “break” When these cracks occur, oil and gas that is trapped in low permeability areas can escape through the large cracks These cracks all begin at the point of our well, so the fluid will come back and be pumped out Fracking really increases the permeability of the reservoir, helping production

Natural Hydraulic Fracturing Hydraulic fracturing was not created by engineers It has been happening for millions of years naturally, whenever pressure is allowed to build above the breaking point Fractures will propagate in the direction of lowest stress Often will begin to go upwards

Why is ‘Fracking’ a topic of debate? There are hundreds of myths about hydraulic fracturing Many people have incorrect scientific facts that spread fear of fracking It has not always had a great past Early on companies made huge mistakes, like not using proper casing, fracking incorrect areas, and allowing frack fluid to flow into local streams/watersheds