Traditional carving implements included adzes, mauls, wedges, chisels, drills, and curved knives, all made of stone; sharkskin was used for sanding or polishing wooden items.
Once operators get a better understanding of a new shale play and climb further up the learning curve, drilling times and costs rapidly drop before leveling out.
Spurred by higher oil prices, enterprising small wildcatters in Texas and Oklahoma were experimenting with new methods: drilling wells that curved horizontally deep underground to intersect layers of gas-bearing shale, then using high-pressure water and sand blasting fissures in the rock, unlocking the gas.
Where image logs are not available, other less rewarding substitutes such as isolated well tests and type curve analysis, drilling mud loss history, core description and conventional petrophysical logs are used for fracture detection.
Figure 11a shows flow curves of drilling fluids with and without barite.
Cabrera drilled a near-perfect backdoor curve from the Chicago Cubs left-hander Paul Maholm, low on the outside corner, for a run-scoring triple, his seventh, which remained the most in baseball.
Logging curves record various physical parameters of the drilled formation, and every single curve reflects one geological feature indirectly and conditionally (Ding 2002).
Mud loss data come from daily drilling reports from Socomine (dark blue curve) and from Hettkamp et al. (2004) (light blue section).
The oblique cutting geometry at each point on the drill lip is modelled using parametric curve equations.
The drilling torque vs. number of holes curves typically exhibited three stages, each identified with a characteristic slope (m).
