Simplify the following text for a Grade 8 native English-speaking person.
Original: Noble Energy , Inc. of Houston , Texas , United States is the modern name of Noble Affiliates Inc. , by which it was known through the 1990s , and it is now an oil and natural gas exploration and production company with almost US$ 3 billion in revenue at # 660 on the 2007 Fortune 1000 list of the largest American companies .
Simplified: Noble Energy , Inc. of Houston , Texas is the modern name of Noble Affiliates Inc. , by which it was known through the 1990s , and it is now an oil and natural gas exploration and production company with almost US$ 3 billion in income at # 660 on the 2007 Fortune 1000 list of the largest American companies .