Texas has been known for its oil wells, so it’s not too surprising that humorous proverbs have developed.
 
 
29 April 1954, Lincoln (NE) Star, pg. 4, col. 2:
Old Texas Saying
Other places have different ways of saying it but in Texas, we understand, when they say a girl marries well they generally mean it’s an oil well. 
 
19 March 1961, Fresno (CA) Bee, pg.  4D photo caption:
An old Texas saying has it that the “fattest steer is one that scratches against an oil well.”