It is very straight forward to identify and locate wells using the on-line GIS-based tool provided by the state of Texas.
The address for the tool is found by following this link
You should select the GIS tool and away you go. I have found it easiest to initially select a county and then zoom in from there. The tool is very useful and well organized.
Note that you will need the well API identification. This is something like a social security number for wells, the number consists of three parts: an operator name, a well number, and a lease name, although this is also commonly state code, county code, series code and company code. A description of how the API identification is constructed is found at this link.
The State of Texas has done a great job making these resources freely available.