I have decades of experience in various prayer groups. I've seen a lot of mistakes.
A church prayer ministry attracts counterfeit Christians and spiritually compromised Christians. After all, they get to lay hands on people and transmit their demons, to compromise the church. Thus volunteers to this ministry need special scrutiny. Just because they were a prayer minister in another church doesn't guarantee the person is straight.
Prayer Group protocol:
Prayer request cards can be handled by the whole group if the requests are few enough. One minister prays and the rest agree. With more cards, the ministers pair off with their part of the cards. One minister prays and the other one agrees. With a large number of cards, scan the cards for prayer topics, stack up the cards and everyone prays over the deck, making sure the topics are hit. All three ways are effective.
A prayer group is a small group like any other. The ministers need prayer time and social time as well. A short Bible study can be added. It is helpful to do things outside the group such as prayer for shut-ins or prisoners. Quiet times should be encouraged.
last update: April 09, 2015 http://orderofsaintpatrick.org/prayer-groups.htm