First turning on the TV at the Hilton hotel in Houston, something most unexpected came on: a commercial advertising the Brown Procedure, an endoscopic treatment for carpal tunnel syndrome.
I was in Houston on a junket visiting Shell International Exploration and Production's Bellaire Technology Center with Biz, Dahua, Dmitry, Hyun, Jin, Venkat, and Vincent alongside. Back in the day when Bell Labs was Bell Labs, the Bellaire facility was the Bell Labs of the oil industry. The mission that the eight of us chose to accept was learning how teams of geologists and geophysicists interpret data, primarily seismic data, to find reservoirs of hydrocarbons from which it might be profitable to extract oil and natural gas.
Dahua summarizes his experience here. Interestingly, since my eyes are now looking for it, I keep seeing articles about this stuff, e.g. these two articles in the December SIAM News and this article in the January IEEE Spectrum.
There are no pools or rivers or streams of oil in the earth's crust. Oil exists in the pore spaces of rocks such as sandstone. The presence or absence of three things make or break a prospect: source, reservoir, and trap. Source means that over geologic time, organic material transformed into oil through heat and pressure. Oil is less dense than rock, so it tends to move towards the surface if possible. Reservoir is a layer of the crust with pore space, a good example being a layer of sandstone. Trap is a geometric arrangement such that the reservoir is surrounded on all sides except the bottom by impermeable layers such as those made of shale. Trap geometries are often the result of faulting, i.e. the cracking and pushing up of some regions leaving other regions below.
In some parts of the world, like under the Gulf of Mexico, the crust contains massive bodies of salt. The salt behaves like toothpaste, getting squeezed and pinched by the weight of the surrounding rock. Importantly, salt is also impermeable to oil.
To image the crust, seismic data is collected. A large amplitude acoustic pulse or chirp signal is input into the ground and the reflections are recorded. Reflections occur from interfaces between different rock types such as sandstone-shale boundaries. Reflections from the same spatial location are recorded many times because a single record has extremely poor signal to noise ratio. The data that is collected for a spatial location is in time, not depth. It must be migrated from time to depth taking the speed of sound in the materials below into account, an ill-posed and challenging problem.
With a seismic volume either in time or depth, the interpreter's laborious job is to pick out faults, salt bodies, and continuous layers of reservoir rock. Then the task is to understand the depositional environments, geology, etc., identify prospects, and finally decide whether the risk to drill them is worth it. (It costs somewhere around one hundred million dollars to drill an exploratory 'wildcat' well.)
Shell has developed some automatic pickers that we got to play around with that somewhat reduce the laborious, repetitive nature of picking faults and events. However, the tools are far from perfect. Interpreters are still subject to much repetitive strain injury such as carpal tunnel syndrome. Now that we have seen the procedure that interpreters go through and what open problems exist, we can contribute to the development of interpretation tools for geologists and geophysicists so that they can focus their time on the higher level, understanding-based tasks of interpretation rather than on the lower level, repetitive tasks.
An eventual goal is to put Dr. Brown out of business and develop a full object recognition system, but that is a long way off.
