What is the meaning "cause i walk like i've got oil wells pumping in my living room?

This poem is about standing up for what you believe in and being strong despite having challenges along the way, especially those aimed at bringing you down. When Maya Angelou states "cause I walk like I got oil wells pumping in my living room":

Oil wells and business in oil production typically leads to wealth, richness, and power.

Angelou is saying that she walks with pride and confidence, despite the challenges she is presented with. This shows strength of character and even though she must push through opposition that comes her way, in the end, she will rise above it all and come out on top.