After a well is drilled and completed, the operator files a completion report: Form W-2 for an oil well, Form G-1 for a gas well. These reports are the source of most of what is known about the hole itself, as opposed to the permit to drill it. The RRC compiles them, along with later filings on the same wellbore, into a wellbore data file that Petrora loads weekly.
What the completion report contains
- Completion date and the lease and field the well is assigned to.
- Total depth as drilled, which often differs from the depth on the permit.
- Elevation of the ground or the kelly bushing, which is what makes depth comparisons across wells possible.
- Formation tops: the measured depth at which each named formation was encountered. The operator names the formations, in the operator's own words.
- Casing strings: size, depth set, hole size, and cement.
- Perforated or open-hole intervals.
- Log references, noting which logs were run.
A well that is recompleted, sidetracked, or re-entered gets another report under a suffix of the same API number. See API numbers.
Formation tops and names
Formation names on completion reports are free text. The same formation shows up as "Wolfcamp", "WOLFCAMP A", "Wlfcmp", and "Wolfcamp Shale" across different operators and decades. Petrora normalizes these to a registry of canonical formations, which is how formation pages can gather wells from across the state. Roughly 85 percent of reported names match the registry; the rest are shown as the operator wrote them. A well page shows the canonical name with the original beside it when they differ.
Subsea depths
Measured depths are useless for comparing two wells on different terrain. A top at 9,000 feet in a well whose kelly bushing sits at 2,900 feet is at the same elevation as a top at 8,600 feet in a well at 2,500 feet. Petrora converts to subsea depth where the well's elevation is known: subsea equals elevation minus measured depth, so most tops in Texas come out negative. The well page shows both.
Where a well has several completions reporting an elevation, the original hole is preferred.
Where to look
Formation tops, perforations, and casing appear on the well page beneath the completions table. The formation registry is the basis of formation pages, which show, for each canonical formation, how many wells report it, its depth by county, which operators drill it, and the most recently permitted wells. County pages list the formations reported in their completed wells.