The Oil Drum

One of my early "scientific" memories was being taught that, after you see a lightening strike, if you start counting the time in seconds until you hear the thunder, then divide by five, this tells you how many miles away the storm is. This is because the speed of sound in air is around 1,100 ft/sec (I say around since it depends on temperature and humidity). In the same way it was fun to stand in a place where you could get an echo when you yelled really loudly.

From which you may surmise that it is time for another techie talk. For those new to the site, this is a post on occasional weekends where I try and simply explain some of the aspects of getting oil and gas out of the ground. The full list of previous posts on the topic is given at the end of the post, and you are asked to remember that this is a relatively simplified discussion that is meant to briefly describe the fundamental ideas.

In the last post I considered that we had drilled into a reservoir, and showed how roughly one might find out how much oil was there. But I did not mention how we found out how large the reservoir was (I used a 200 ft thick, block of rock that measured 1,000 ft in length and width to make the calculations easy and obvious). So this week perhaps we can talk about why we think the field is a thousand ft wide and long. (We ultimately physically measure the 200 ft dimension).