That's a very important question.It will be the responsibility...

That's a very important question.
It will be the responsibility of management to negotiate with WDS in relation to that cost.
I think that there are a number of scenarios which could be considered.
1. Share price appreciates significantly on the announcement of the drilling beginning ...... PCL raises capital by issuing shares to soph Investors to raise the $20 million for our share of well 2.
This IMHO is the path they will follow as it will fund a second drill if the first comes up dry(unlikey IMHO) without PCL reducing their percentage.
2. First drill is successful and PCL share price jumps significantly ....... again PCL management raise the $20 million with soph investors with a much smaller dilution. Can be achieved very quickly.
3. First drill is successful and WDS loan or allow credit for PCL to have time to raise the necessary capital. This will depend on the negotiability skills of PCL management and the overall good will between the parties. Unlikely IMHO .... WDS will still be gun shy after their dealings with FAR (another minor company who got too big for their boots).
4. First Drill is dry and PCL share price tanks and management opt for the 10% clause and reduce our ownership in exchange for being free carried for the second well. A second well would be drilled much later IMHO as there would be a period that WDS would be reappraising their 3D to reassess the drill location for the second well.
5. Any successful drilling will, IMHO, attract suiters who will want to take over PCL, the price is then the major contemplation .........