Adding More Wells?

I have property in Utah and most of our land is leased to oil companies. My question is: We have about 15 wells now with potential for 100 more. What/who determines how many and when new wells will be developed? I would think this is dictated by the oil companies themselves? Thanks.

Jeff:

The oil companies geologists/engineers play a major role in adding additional wells to a unit based on the density , costs, etc. Applications must be made and approved by the Utah Division of Oil, Gas and Mining.

Thank you Charles. So, to clarify...the oil companies pretty much "drive" new well activity then? As a land owner, I would not gain much by trying to "market" or "promote" the land they are already leasing from me? Just wondering since the pace of new wells is not as fast as I would like to see but sounds like I probably have little control over it.