Petroplex (Midland/Odessa nickname)

“Petroplex” is an imitation of “Metroplex” (Dallas/Fort Worth, trademarked from January 1972). The west Texas cities of Midland and Odessa—where petroleum is the most important industry—have used the “Petroplex” nickname since at least November 1975.
 
Another Texas “-plex” is “Centroplex” (Belton/Killeen/Temple, cited in print since at least February 1977).
   
   
Wikipedia: Midland, Texas
Midland is a city in and the county seat of Midland County, Texas, United States, on the Southern Plains of the state’s western area. A small portion of the city extends into Martin County. As of 2009, the estimated population of Midland was 108,668. It is the principal city of the Midland, Texas Metropolitan Statistical Area, which includes all of Midland County. The metropolitan area is also a component of the larger Midland–Odessa, Texas Combined Statistical Area, which had an estimated population of 266,941 as of July 1, 2009. People in Midland are called Midlanders.
 
Midland was originally founded as the midway point between Fort Worth and El Paso on the Texas and Pacific Railroad in 1881. The city has received national recognition as the hometown of former First Lady Laura Bush and the childhood home of former President George W. Bush.
 
Wikipedia: Odessa, Texas
Odessa is a city in and the county seat of Ector County, Texas, United States. It is located primarily in Ector County, although a small portion of the city extends into Midland County. Odessa’s population was 96,943 at the 2000 census. As of 2009, the population of Odessa was 100,807. It is the principal city of the Odessa, Texas Metropolitan Statistical Area, which includes all of Ector County. The metropolitan area is also a component of the larger Midland–Odessa, Texas Combined Statistical Area, which had a population of 261,435 as of July 1, 2008. estimate.
   
Wikipedia: List of city nicknames in Texas
Midland - Petroplex (shared with Odessa)
Odessa - Petroplex (shared with Midland)
   
2 November 1975, Midland (TX) Reporter-Telegram, pg. 11A ad:
KNORR’S FURNITURE
SERVING THE PETROPLEX
   
17 March 1977, Midland (TX) Reporter-Telegram, “State bowling fever arrives” by Randy Isenberg, pg. 3D, col. 2:
The State tournament enters its second weekend in the Petroplex cities of Midland and Odessa.
 
9 December 1979, Dallas (TX) Morning News, “Metroplex is nowhere unles you live here” by Steve Blow, pg. 6A:
As “metroplex” infiltrated the local vocabulary, it also began to spread geographically. It wasn’t long before Midland-Odessa was calling itself “the petroplex,” and the Temple-Belton-Killeen area dubbed itself “the centroplex.”
   
Google Books
May 1981, Texas Monthly, pg. 124, col. 2:
But then again, the Midland-Odessa “petroplex” has no shortage of oil industry types to keep museum director Homer Fort from getting lonesome.
(Permian Basin Petroleum Museum—ed.)
 
8 July 1981, Paris (TX) News, “Oil boomtown of Midland gropes for direction,” pg. 5B, col. 8:
But until that happens, until the Midland-Odessa region—which calls itself the “Petroplex”—becomes a true metropolitan area, Barclay remains skeptical about convincing non-oil businesses to relocate to the Permian Basin.
 
Google Books
August 1984, Texas Monthly, pg. 104, col. 2:
Letter From the Petroplex
Can Midland and Odessa really kiss and make up?

(...)
They even have a catchy slogan, “Midland/ Odessa: We’re Better Together.” Well, kinda catchy. Still, after a couple of days in the Petroplex, I returned home wondering why they are even bothering.
 
29 December 1985, Dallas (TX) Morning News, “‘Golden Triangle’ name game’s goal is rejuvenation” by Steve Blow:
In so doing, the area joins ranks with the Metroplex (Dallas-Fort Worth), Petroplex (Midland-Odessa) and Centroplex (Temple-Killeen) among others.