Working through the descriptions is logical if you read from right to left.
Set one- “Lot 4” look up on the BLM maps. Search documents. OKLAHOMA> 9 North and 4 West Indian Meridian -Master Title Plat Home - BLM GLO Records Zoom into section 31 and you will find that Lot 4 has 39.95 acres. (Essentially this one is the SW4 SW4) Note: the Northern and Western tiers of sections are frequently corrected for the curvature of the earth, so the quarter sections on the edges are not always 40 acres.
“SW4 SE4 SW4”-read from right to left. The SW 4, then SE4, then SW4 is 10 acres. (The SW has 160 acres, then 1/4th of that which is 40 acres in the SE 4, then 1/4th of that which is 10 acres in the SW4.)
“S/2 SE4 SE4 SW4” read from right to left. The SW4, then SE4, then SE4, then S/2. (The SW has 160 acres, then 1/4th of that which is 40 acres in the SE4, then 1/4th of that which is 10 acres in the SE4, then the south half of that SE4 which is 5 acres) 5 total acres. Notice that it is contiguous to the previous one. The most you have there might be 39.95 acres plus 10 acres plus 5 acres. 54.95 acres is the max possible. It says you have an undivided interest. If you have any siblings or other heirs, then that might be further split by the will. If you are the only one, then perhaps you have the full 54.95 acres. These are in blue on the map below.
2nd set- SE4 SE4 SW4 29-9N-4W. Same thing. 160/4, then 40/4 = 10 acres. In red on the map.
3rd set- “NW4” full 160 acres. “W2 NE4” = 80 acres “NW4 SE4 NE4” = 160/4, then divide by 4 again for 10 acres. So perhaps the 250 acres, but maybe not if your ancestor had some percentage of that or you have other heirs at your level.
The title folks who do the searches go back farther in time and figure out the splits based upon the original deed and all the generations title splits. For example, if grandpa had an undivided 160 acres in the NE4, but he had four children, then they would possibly inherit 40 acres each depending upon the wording of his will. Then the next generation would fractionate it even more. Did the executor have all that other information? Frequently, an exhibit will have extra words in front of that “undivided interest” such as "A 1/32 of the undivided interest… " If it passed from one person to one person, then it could stay as the original parcels, just unusual.
At least this helps you visualize it.