When we think about the boom in shale oil here in the United States, many of us chalk up its success to the advances in hydraulic fracturing and horizontal drilling. Yes, these technologies were a very important part of the equation, but being able to access all of that oil requires something else as well: We need to know where it is.

This is an aspect of the shale boom many of us tend to forget. Unlike other traditional exploratory efforts, we have known where these shale oil deposits were for decades. This has allowed shale drilling specialists like Pioneer Natural Resources (NYSE:PXD) to have a 97% success rate on exploratory wells versus the 80% range for big oil players like Chevron (NYSE:CVX). Find out how this high probability of success impacts the investment decisions of shale drillers like Pioneer and Devon Energy (NYSE:DVN) by tuning into the video below.