It sounds like your lease (or perhaps someone else's) does not allow for pooling, or has a limitation on what can be pooled. Generally speaking I am of the opinion that Pooling is fair so long as a portion of your tract does not get excluded from a unit. You are probably ok to sign but I would at least call and ask why this is necessary and have them explain the unit size and make sure both tracts are included in the unit (you should be able to determine that from the paperwork).