The television show The Beverly Hillbillies in 1962 had a theme song that called oil “Texas tea.” There have been other meanings attached to “Texas tea,” including actual tea.
 
     
Wikipedia: The Beverly Hillbillies
The Beverly Hillbillies was a TV sitcom about a hillbilly family living in Southern California in the 1960s.
 
The patriarch strikes oil while hunting on his land near a fictionalized hamlet called Bugtussle in the Ozark Mountains. He then listens to the advice of friends, neighbors and extended family members, and moves with his family to Beverly Hills, California, with the resultant wealth.
(...)
The theme song, “The Ballad of Jed Clampett,” (listen) was written by producer and writer Paul Henning and originally performed by Bluegrass artists Flatt and Scruggs. It was #44 on the music charts in 1962. 
     
Bluegrass Lyrics
Ballad Of Jed Clampett
Come and listen to a story ‘bout a man named Jed
Poor mountaineer barely kept his family fed
Then one day he was shooting for some food,
And up through the ground come a bubbling crude
(Oil that is, black gold, Texas tea)
   
DrinksMixer.com
Texas Tea recipe
INGREDIENTS:
2 oz tequila
2 oz rum
2 oz vodka
2 oz gin
2 oz bourbon whiskey
2 oz triple sec
2 oz sweet and sour mix
Coca-Cola®
 
DIRECTIONS:
Fill a 1 gallon pitcher with ice. Add all the ingredients except the coca-cola. Stir, then add the coca-cola and stir again. Pour into your favorite glass with ice and enjoy. 
 
Urban Dictionary
texas tea
Another name for promethazine w/ codeine; aka barre, lean, sizzurp, oil, purple stuff, Memphis mud, drank, purple jelly, etc. Real popular in H-Town; mix it up with some Sprite, crushed ice, and jolly ranchers, and get ta sippin’...
Let’s po’ up a deuce of some Texas tea and start leanin’...
by headbussa_666 NYC Jun 26, 2005
   
Texas tea
The term “Texas Tea” was originally used to describe oil, and was popularized by the hit 1960s television show, The Beverly Hillbillies: “Oil that is, black gold, Texas tea.”
Today, the term can also be found in your local bar as it represents the name of a mixed drink, also by the same name:
Texas Tea:
2 oz Tequila
2 oz Rum
2 oz Vodka
2 oz Gin
2 oz Bourbon Whiskey
2 oz Triple Sec
2 oz Sweet and Sour Mix
Coca-Cola
Then one day he was shootin at some food,
And up through the ground came a bubblin crude. Oil that is, black gold, Texas tea.
by Giskard Jul 6, 2004
   
9 August 1965, Chicago (IL) Tribune, pg. C4:
ARLINGTON PARK COMMENT
(...)
Texas Tea
(The name of a horse—ed.)
   
3 September 1968, Chicago (IL) Tribune, pg. C8:
Rush for Icy “Texas Tea”
(Alaska oil pipeline story—ed.)
   
(Trademark)
Word Mark TEXAS TEA
Goods and Services (CANCELLED) IC 020. US 050. G & S: Novelty Item Comprising a Shaped Container for Liquids. FIRST USE: 19801230. FIRST USE IN COMMERCE: 19801230
Mark Drawing Code (1) TYPED DRAWING
Design Search Code
Serial Number 73387296
Filing Date September 21, 1982
Current Filing Basis 1A
Original Filing Basis 1A
Published for Opposition November 1, 1983
Registration Number 1265014
Registration Date January 24, 1984
Owner (REGISTRANT) Texas NRG Corporation CORPORATION TEXAS P.O. Box 1134 Seguin TEXAS 78155
Attorney of Record John C. Stahl
Disclaimer No claim is made to the exclusive right to use the word “Texas”, apart from the mark as shown.
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator DEAD
Cancellation Date November 4, 1992
 
(Trademark)
Word Mark TEXAS TEA
Goods and Services (ABANDONED) IC 030. US 046. G & S: ready to drink iced tea
Mark Drawing Code (1) TYPED DRAWING
Design Search Code
Serial Number 74538004
Filing Date June 15, 1994
Current Filing Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) U. S. BEVERAGE CO. CORPORATION TEXAS 1800 Judson Road Longview TEXAS 75601
Attorney of Record Chrys D. Lemon
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator DEAD
Abandonment Date June 20, 1995
 
(Trademark)
Word Mark TEXAS TEA!
Goods and Services (ABANDONED) IC 032. US 045 046 048. G & S: canned or bottled tea
Mark Drawing Code (3) DESIGN PLUS WORDS, LETTERS, AND/OR NUMBERS
Design Search Code 01.01.03 - Comets; Stars with five points
01.01.10 - Stars, three or more; Three or more stars
02.01.07 - Cowboys; Men, cowboys, and westerners; Westerners
02.01.31 - Men, stylized, including men depicted in caricature form
02.09.17 - Humans, including men, women and children, depicted riding horses and other animals
Serial Number 74631698
Filing Date February 8, 1995
Current Filing Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) Montego Bay Beverage, Inc. CORPORATION ILLINOIS 1310 W. Deerpath Lake Forest ILLINOIS 60045
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator DEAD
Abandonment Date March 1, 1996
   
(Trademark)
Word Mark TEXAS TEA
Goods and Services (CANCELLED) IC 037. US 100 103 106. G & S: Vehicle preventive maintenance services and repair. FIRST USE: 19960700. FIRST USE IN COMMERCE: 19970905
Mark Drawing Code (1) TYPED DRAWING
Design Search Code
Serial Number 75381865
Filing Date October 30, 1997
Current Filing Basis 1A
Original Filing Basis 1A
Published for Opposition October 20, 1998
Registration Number 2217233
Registration Date January 12, 1999
Owner (REGISTRANT) Texas Tea Service, Inc. CORPORATION CALIFORNIA 5560 Dwight Avenue San Jose CALIFORNIA 95118
Type of Mark SERVICE MARK
Register PRINCIPAL
Live/Dead Indicator DEAD
Cancellation Date October 15, 2005
 
(Trademark)
Word Mark TEXAS TEA
Goods and Services IC 009. US 021 023 026 036 038. G & S: Gaming machines; namely, slot machines with or without a video output. FIRST USE: 19990923. FIRST USE IN COMMERCE: 20000512
Mark Drawing Code (1) TYPED DRAWING
Design Search Code
Serial Number 75762855
Filing Date July 29, 1999
Current Filing Basis 1A
Original Filing Basis 1B
Published for Opposition February 29, 2000
Registration Number 2441609
Registration Date April 3, 2001
Owner (REGISTRANT) IGT CORPORATION NEVADA 9295 Prototype Drive Reno NEVADA 89511
Attorney of Record SANA HAKIM
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator LIVE
 
(Trademark)
Word Mark TEXAS TEA
Goods and Services IC 033. US 047 049. G & S: Distilled spirits
Standard Characters Claimed
Mark Drawing Code (4) STANDARD CHARACTER MARK
Design Search Code
Serial Number 78632117
Filing Date May 18, 2005
Current Filing Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) Bison Capital LLC Greg Betterton - USA LTD LIAB CO FLORIDA Suite 105 981 Ridgewood Ave Venice FLORIDA 34285
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator LIVE
 
(Trademark)
Word Mark TEXASTEA
Goods and Services IC 004. US 001 006 015. G & S: Engine oils; Lubricating oil for motor vehicle engines; Motor oil
Mark Drawing Code (3) DESIGN PLUS WORDS, LETTERS, AND/OR NUMBERS
Design Search Code 01.01.03 - Comets; Stars with five points
09.05.05 - Sombreros, cowboy hats (10 gallon hats), other broad-brimmed hats
Serial Number 78820040
Filing Date February 21, 2006
Current Filing Basis 1B
Original Filing Basis 1B
Owner (APPLICANT) Silver, Michael, Craig INDIVIDUAL UNITED STATES 211 Woodhill Court Tahoe City CALIFORNIA 96145
Description of Mark The mark consists of A stylized cowboy hat with a star in the center of the hat and the word TEXASTEA below the hat.
Type of Mark TRADEMARK
Register PRINCIPAL
Live/Dead Indicator LIVE