Oil Ledger — what it is, in short

What this is:

OLA013K, the oil master tape -- the schedule the Railroad Commission runs the oil business on. Eleven district volumes of 1200-byte EBCDIC records, decoded here into eight tables: a record for every oil FIELD, the LEASES in it, the MULTI-WELL groups on a lease and the individual WELLS, each with the months the tape carries inside the record.

How it is laid out:

The Railroad Commission publishes this as EBCDIC (IBM cp037). IBM mainframe encoding (cp037). Opening it as text gives you nonsense; it has to be transcoded first. We decode it into a table you can open anywhere. It has 263 columns and about 33.9K rows.

The columns you will most likely want:

district RRC district the field is in, as the ledger tape writes it: 01-06, 06E, 07B, 07C, 08, 08A, 09, 10 -- the lettered four carry a leading zero the W-10, the G-10 and PDQ do not use.
field_no The eight-digit RRC field number: five digits identifying the field and three more for the reservoir.
operator_no Zeros on every field record -- the tape repeats the full key layout on all four record types and a field has no operator.
lease_no Zeros on every field record, for the same reason as operator_no: the key layout is shared with the lease, multi-well and well records.
offshore Where the field's discovery well sits: 0 land, 1 state bays and estuaries, 2 state offshore from islands, 3 federal, 4-9 the combinations.
field_name The field name as RRC designated it, usually an operator's word plus the formation and its depth: 'A.W.P.

…and 257 more, all documented on the full page.

What we add:

Read the rules a field is prorated under -- the allocation formula and its weights, the yardstick, the acres and footages a proration unit must have -- and put a lease's or a well's allowable in the context of the field that set it.

There is more on the full page, including what this joins to.

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:

The district is spelled the tape's way: 06E, 07B, 07C and 08A, with the leading zero. The W-10, the G-10 and PDQ write 6E, 7B, 7C and 8A. A join on the column as it stands silently drops those four districts -- 24% of the ledger's wells -- so strip the leading zero first.

The full page lists every trap in this dataset.

Get it:

People who want this usually want:

Oil Ledger — Field Months Fourteen months of allocation factors for every oil field.
Oil Ledger — Leases Every oil lease on the proration schedule, with its gatherers and its balances.
Oil Ledger — Wells Every oil well on the proration schedule, with its depth, status and last test.
PDQ Field Directory The field number to field name lookup, with class, discovery date and rules flags.
Oil Ledger — Multi-Well Groups Waterflood and secondary-recovery groups that take a lease allowable instead of well allowables.
Gas Ledger The gas proration schedule: every gas field in Texas and how its allowable is set.