Wow!

"And, it is hundreds of metres deep in places, whereas the average oil-bearing strata may only be a few metres thick"

The captain has obviously been well educated and is pleased to be able to show off his knowledge.

"An SL's job is to collect the gas and wood from the miners and deliver it to LP Central, hence the interesting design of this ship"

And where is LP Central?

"It's located in 40m of water and is about 20km south of the geometric centre of the concession"

and what happens to it there?

"Some of the wood is burnt in a power plant to make electricity, and some is exported.  The gas is compressed to pipeline pressure and the heavier fractions (LPG) are extracted; quite a lot is converted to hydrogen.  Gas, hydrogen and electricity currently go to the Belém area and are gradually being introduced into the whole of Pará province"

And what about the CO2 produced?

"Don't worry, it all collected and sent for ocean sequestration.  All the major users return their CO2 to LP Central.  Minor consumers use hydrogen."

Our boat has been speeding along for a couple of hours by now, and the captain explains that she is one of three high-speed SL's which often do the Belém run, taking wood and LPG back to the shore and bringing containers of supplies out to the miners.  There are also six GL's (Gas Lighters) which just ferry gas from the gas Miners to the GSL's (Gas Loading Stations) and return with hydrogen.

What is a Gas Loading Station?

"Well, the miners are on the move all the time, so you can’t run a fixed pipeline to them.  However, it would be uneconomic to ship the gas all the way to Central, so the GLS's are a compromise.  They are transfer points from the SL's to a pipeline system.  Each GLS has six Gas offloading Pillars and three Hydrogen loading Pillars… but you will see all that later!"

And how many GLS's are there?

"There are currently three, but a fourth will be opened in a couple of years time, as the working area expands."

What is the wood used for?

"Well, a huge amount of wood is used for cooking in a town the size of Belém with a population of nearly 2 million, not to mention the rest of Brazil.  The government prefers people to use 'mined wood' rather than cut down more of the rain forest, as previously.
Recently, however, there has been increased demand for quality 'mined wood' from furniture makers.  Apparently its 'well seasoned' and 'green label' characteristics make it a very popular export commodity.  Most of the wood comes out as flakes, but sometimes usable logs are found".

And the LPG?

"Well, vehicles mainly… but look, there's our first LP Miner coming up.  This one's a wood miner so we're going to take some wood and gas aboard; no point in running around empty"
He is pointing at an island ahead with several houses on it.  There's a jetty with a small coaster loading, but we're headed for a mooring on the other side.
"As I was saying," said the captain "it's more like a cottage industry; he's selling his mined logs plus a lot of firewood, to the coaster who will no doubt be taking them to Belém."