Warwickshire ended the first day 370 for three in what is the traditional First Class season curtain-raiser between last season's County Championship winners and a MCC XI.
After winning the toss and electing to bat in the day/night match, Dougie Brown's side suffered an early blow when Ian Westwood was caught by Simon Kerrigan off Peter Trego for a four-ball duck. That however brought Porterfield to the crease as he and Chopra put on 307 for the second wicket.
MCC's spinners, Simon Kerrigan, James Middlebrook and Dawid Malan all struggled as Chopra reached three figures off 165 balls, with his partner reaching the landmark shortly after off three fewer deliveries.
The MCC finally made a breakthrough after tea when Chopra was caught by Steve Kirby off Kerrigan for a 246-ball 163, in a knock which included 20 fours and three sixes.
Porterfield put on 42 with Laurie Evans before the Irishman went for 162.
Durham's Chris Rushworth was the bowler with Kerrigan taking another catch in the covers to end Porterfield's 240-ball effort, which included 22 fours and a six.
Evans ended the day unbeaten on 15, while Jim Troughton was eight not out.