Several people have asked us some or other stuff related to the drilling, testing, and production for natural gas. So far, we’ve responded by pointing out that we are no technical specialist and we limited knowledge in these fields. However, we are aware of some sources for the hobbyist to enhance one’s knowledge at least a little.
We immediately have to start on a rather disappointing note, we can’t find our best link. However, there are a couple of others. Quite useful for the layperson is ‘how stuff works’
Another resource with a useful intro:
A couple of quotes that have bearing in the present situation at InterOil:
Open hole completions are the most basic type and are only used in very competent formations, which are unlikely to cave in.
We have some reasons to believe that they are at least considering an open hole test, the advantage of this is that it is more likely to produce better flow rates, it’s not without risk though, and we also belief that there is enormous pressure in the well, so they might not risk it.
Because it is a low-density gas under pressure, the completion of natural gas wells usually requires little more than the installation of casing, tubing, and the wellhead. Unlike oil, natural gas is much easier to extract from an underground formation.
Nice to keep in mind. Getting the gas out that is there under such pressure is, apart from keeping the well safe (and most efforts towards this have already been taken). No need for fracturing or acid to increase the flow rates.
It’s about (heavy) oil, but some of the descriptions apply
This one even has pretty pictures..
There were question about porosity, a crucial variable determining how much resource a rock (or sand) can hold. Here some useful stuff from oilandgastraining.com
Forms of Porosity
Porosity may develop in a formation by a variety of mechanisms. Where pores are uniformly distributed throughout the bulk rock, the porosity is referred to as matrix porosity. Where the only storage space in the rock system is in cracks and fissures in an otherwise zero porosity matrix, the porosity is referred to as fracture porosity. A third type of porosity may coexist with either of the other types in the form of vugs, and is referred to as vuggy porosity.
Matrix Porosity Matrix porosity is common in sandstone and other granular rock formations. The physics of the porosity measurement is unaffected by the manner in which the void spaces were created; i.e., it is not important whether the porosity was originally created by sedimentation of individual grains or by leaching by acidic solution after deposition. Thus, individual logging tools cannot tell directly the type or origin of the matrix porosity in a rock sample. Petrographic analysis of cores is required for that kind of information.
Fracture Porosity Fracture porosity is unevenly distributed throughout the rock. It appears normally as near-vertical cracks, or fractures, whose orientation depends on the azimuth of the stresses in the formation. Not all logging tools respond to fracture and/or vuggy porosity in the same manner. Thus, it is sometimes possible to distinguish fracture and/or vuggy porosity from matrix porosity with judicious use of a combination of porosity-measuring devices and careful analysis of the results. (A difference in porosity measurements derived from a Neutron/Density suite and that provided by a Sonic tool can sometimes be attributed to this type of fracture porosity.)
Vuggy Porosity Vuggy porosity is most often encountered in limestone formations. It occurs when small cavities are formed as the rock material passes into solution. Vuggy porosity is most often a type of ineffective porosity due to the fact that the small cavities are isolated from each other. If Swiss cheese were a type of rock, it would be characterized as having vuggy porosity.
We’re still hopeful we will find that prime source one day. If you feel you have something to add, don’t hesitate!
We’ve also composed a primer on resource classification and how the SEC deals with that (and how it’s going to change). You can find it here: