A long winded post for those with patience...after all it is...

A long winded post for those with patience...after all it is Sunday and the cricket is a bit slow!

Although pressure in Atocha was measured at 10,000psi, the volume of gas coming through the perforations was insufficient to 'push out' the column of fluids above which, as noted in O & G weekly today, "You need to fill a well bore up with water before you set off the explosions that result in the perforations otherwise you risk blowing the well to bits!

And, the PRA et al ASX releases, in part, "On perforation the well produced natural gas and built up pressure, however not enough to produce back approximately 90 barrels of completion fluid placed in the well by the operator for the logging and perforation procedures. Further pressure testing resulted in a gradual accumulation of 10,000 psi. The fluid creates pressure against the formation, thus restricting the flow of natural gas. The slow pressure build up also confirms the tight nature of the formation and confirms the possibility of fracture stimulating the formation, which was originally planned and budgeted for at the beginning of the reentry."

But, this restriction of the flow of natural gas appears a problem that most wells in the US have in common; lack of initial flow requiring stimulation and fraccing.

I tried to check out the O & G weekly comment about the water requirement for perforation by, da dah! ---- wait for it ----googling: but without apparent success in the million or so answers in 0.34 seconds - damn! :( Then again, I was a bit distracted by the dismissal of Ponting for 36 :(

BUT! In the search process, I found the following site that goes a long way to explaining the problems associated with perforations and an alternative process that seems to overcome the problems:

http://www.gulfoilandgas.com/webpro1/MAIN/Mainnews.asp?id=9424

I'll quote the article in full for those who have a phobia about cutting and pasting (it does not appear to be a problem for most HC posters who would be speechless without this technology...but I'll c&p the article anyway so that readers retain the the central idea of this looong post)

"Aramco Uses Laser Technology in Well Perforation
Source: www.gulfoilandgas.com 10/14/2009, Location: Middle East
Logging, Perforating, Testing

In gas and oil well completion, perforation of a well is an essential step for hydrocarbon fluids to flow from the reservoir rock into the wellbore and onward to the surface. Perforations are holes made through the steel casing wall and cement into the rock formation. However, the current industry technique, which uses explosive-type charges, causes compaction in the rock, reducing the ability of the hydrocarbons to easily flow into the well.

To avoid such damage to the rock formation, the EXPEC Advanced Research Center (EXPEC ARC) has achieved successful stages in developing a new perforation method using laser technology, making Saudi Aramco the first to introduce in-situ laser perforation to the petroleum industry. The research and development of “in-situ lasing” is being undertaken in collaboration with Halliburton.

“The implementation of this innovative technology will open the door for significant applications in our oil and gas industry, furthering our major goals of reducing costs and increasing production,” said Mohammed Y. Al-Qahtani, executive director of Petroleum Engineering and Development.

Laboratory results have demonstrated that laser perforation generates thermal stresses that fracture a well’s surrounding rock, thus increasing permeability around the perforations, facilitating easier intake of hydrocarbons. An immediate application of laser perforation includes facilitating hydraulic fracturing in open-hole horizontal wells (oriented fracturing), which can greatly enhance the wells’ production capability. Laser technology has significant advantages over the conventional perforation technology, in that there is no compaction. A high-energy laser beam can vaporize rock formation and create a perforation with a permeable wall surface.

“This successful lab laser perforation of casing and rock samples has brought us closer to deploying laser energy in-situ for well perforation and fracture initiation,” said Nabeel S. Habib, Production Technology Team chief technologist. “This in-situ laser perforation will also set the groundwork for further research and applications in petroleum engineering, including laser drilling.”"

Back to Atocha.

We have a good column of over 125 feet of bypassed Tuscaloosa pay sand which has been confirmed by the current pulse neutron cased hole log, and the cement bond log,together with the presence and the permeability for natural gas at the expected zones, in accordance with the original well log data produced by Shell Oil in 1980.

and

A second Tuscaloosa formation has now been confirmed as having gas production potential.

but currently; bugger all gas!

Why? We have learnt from various sources, including HC posts, that the drilling process consolidates the walls of the hole by mechanical compaction of cuttings into the wall of the well, the fluid creates pressure against the formation thereby restricting the flow of natural gas, drilling fluid at a depth of approximately 17,700 feet can stuff up a reservoir by blocking the formation pores

and

now another potential cause of gas flow restriction which has not been explained by the operator, the perforation process itself, consisting of perforating guns with a string of shaped charges lowered down to the desired depth and fired to perforate the casing or liner, can compact the gas bearing formation around the blast holes thereby blocking the flow of gas.

Also:
http://en.wikipedia.org/wiki/Perforation_%28oil_well%29

"perforating can lead to "skin damage", where debris from the perforations can hinder productivity of the well. In order to mitigate this, perforating is commonly done underbalanced (lower pressure in the well bore than in the formation) as the higher formation pressure will caused a surge of fluids into the well at the point of perforating, hopefully carrying the debris with it. Other methods of stimulation such as acidizing and proppant fracturing are often required to overcome this damage and bring the well up to its full potential."

So! Although the sp of the three Musketeers took a negative view on the release of the ASX Atocha Project Update, we are only part way along the track to what is shaping up to be a successful outcome; hopefully before Christmas.

Now! back to the cricket...

I hold PYM & PRA which have boring HC sites so I post here as well where there is more appreciation of effort!!