I own property next to oil companies that are extracting oil from under my property am I entitled to royalties

If your dad owns the mineral rights related to that real estate, he needs to find someone to lease and develop the mineral interests. The other wells you are referring to are generally allowed to "drain" the interests of other owners, with some exception.

Texas subscribes to the rule of capture. By this I mean that the remedy that a mineral interest owner has for being drained by a neighbor is to drill his own well and thus "capture" the transient oil and gas from under his land before it flows out of his neighbor's wells. Royalties are only payable in the event that your dad has leased his minerals to an oil and gas company, and that company has obtained oil and gas from under his lands, or lands that have been pooled with your father's land.

I agree with the answers provided by the two attorneys above. That is, unfortunately, you are not entitled to any of the drainage or production that may or may not be coming from your land. While this may appear bad, it may in fact be a blessing in disguise. Often, production companies are unwilling to stake their claim on a unproven area (or "wildcat") and even if they are interested in your lands may not pay a premium price. Having a producing well next to your property may give other producers the confidence and incentive to lease your lands. I recommend that you get in touch with an oil and gas attorney that has connections with landmen and production companies and to see if there might be someone interested in leasing your lands.