Hi Charles -
By the oddest coincedence, I happen to presently be assisting another family sort out a mess that - you guessed it - an Uncle (and in this case I suspect an Aunt) created involving the family's interest in the Tinsley Field. If you would like me to assist you as well, I will be happy to do what I am able.
Briefly, the Tinsley Field is located in Yazoo County, Mississippi. It is presently being produced under a mixture of Waterflood and CO2 injection driven secondary recovery projects - made up of individual Well Units originally drilled as far back as the 1930's, I think.
I have only performed a cursory review of the records on the field, but it appears that there is a fairly good sized waterflood project on the north end that is compiled of all or parts of about 6 Sections of land (each being a mile by a mile, or 640 square acres) and a second, smaller waterflood project on the south end that totals about 2-1/2 to 4 Sections or square miles.
In between these two waterflood projects is the large CO2 injection project, which covers all or parts of about 30 Sections of land.
Although your records appear to indicate that your family's interest is in only 4 wells, I suspect that those may only be the "original" 4 wells your family had interest in. When those 4 well Units were pooled with other wells into a FIELDWIDE UNIT, such as the three Units I described above, your family then began receiving royalty income from ALL OF THE WELLS IN THE POOLED UNIT.
Like I mentioned, my research thus far has only been preliminary, but in the case of the CO2, that might be hundreds of wells, depending upon what acre spacing they were originally drilled under.
Secondary Recovery Projects such as waterfloods and CO2 Injection projects can result in A WHOLE LOT OF OIL BEING PRODUCED.
I have had to forewarn the other family I am assisting to not get too excited yet and I forewarn you now just as well: We don't yet know for certain which Units you are in and we don't know what your percentage interest or decimal interest is in the Unit(s). Even if your family owned 100% of the mineral interests in the 4 original wells, your interest in the huge CO2 Unit and whichever, if either, of the waterflood projects your family's interest is included in might be very, very, very small.
Having said that and being assured that you are now fully forwarned about allowing yourself to slip into irrational thought or behavior, in 2009 (the most recent year for which I have been able to discover Field Production total figures for so far) the Tinsley Field was rated the 73rd largest Oil Field in the United States, producing something in the neighborhood of 1.7 million barrels that year.
I have one of those pesky little Day Jobs that I have to dedicate at least some of my time to, but if you will send me what information you have regarding the issue I will be happy to take a look and see what I can find out.
I will be inviting you to be "A friend" on the Forum so that we can trade personal contact information. Direct email is the only way I have ever successfully exchanged information with the people I have met through the Forum. For some reason, it just doesn't like my uploads.
Hope this helps -
Charles Emery Tooke III
Certified Professional Landman
Fort Worth, Texas