Wellbore Casing Records — what it is, in short

What this is:

Record type 05. One row per casing string: the casing diameter as a whole number plus a fraction, the depth it was set to, the hole size it went into, how much cement was pumped and how the top of cement was determined. 1.7 million casing strings. This is the dataset behind almost every groundwater-protection question asked about Texas wells.

How it is laid out:

The Railroad Commission publishes this as Fixed-width ASCII. Columns are byte ranges with no separators, described only in a scanned record layout. We decode it into a table you can open anywhere. It has 17 columns and about 1.6M rows.

The columns you will most likely want:

api_county The three-digit county component of the API number.
api_unique The five-digit well component of the API number. Unique only in combination with the county code.
casing_count Sequence of this casing string within the bore.
cas_inch Casing diameter, whole inches.
cas_frac_num Numerator of the fractional part of the casing diameter.
cas_frac_denom Denominator of the fractional part of the casing diameter.

…and 11 more, all documented on the full page.

What we add:

Check whether surface casing was set below the base of usable-quality water, compare cement volumes against hole volume, and find wells whose casing programme is unusual for their field.

Decoded out of the Commission's original format into something Excel opens.
Filterable before you download, so you can take one county instead of the whole state.
The Commission's single-letter codes translated into words.

Worth knowing before use:

Casing and hole diameters are stored as three separate integers — a whole number, a fraction numerator and a fraction denominator. 9 5/8 inch casing is 9, 5 and 8. Reassemble before you compare anything. The cement measurement code says whether the amount is sacks or cubic feet.

The full page lists every trap in this dataset.

Get it:

People who want this usually want:

Full Wellbore Database (ASCII) Every well ever assigned an API number in Texas, with casing, tubing, perforations, formations, plugging and inactive-well tests.
Completion Information in Data Format Forms G-1 and W-2: the filings that turn a drilled hole into a producing well.
Completion Casing Records Casing strings as reported on the completion filing.
Completion Formation Records Formation tops as reported on the completion filing.
Completion Production Intervals The intervals a completion produces through, including open-hole sections.
Completion Stimulation Materials What was pumped into the well, over what interval, at completion.