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gold_well_formation_tops

Formation top picks: one row per well per geologic formation penetrated, with the measured top depth (TVD and subsea). Sourced from completion reports, well logs and scout tickets; this is the input data behind our gridded formation surfaces.

Access tier: portal Portal. These rows are well-level or producing-unit-level data, or our modelled output at cohort or grid grain. They open with a Portal, Pro or Enterprise plan. The website shows aggregates built from them, never the rows.
Primary key: well_id, formation
Region codes: ab, mi, mt, nd, oh, tx, ut, wv, wy

Columns

Column	Type	Nullable	Description
well_id	string	no	Join key to the well register. Part of the primary key together with formation.
formation	string	no	Formation name for this pick, as the region's builder normalizes it. Case conventions differ by region today (several regions publish uppercase names), so the same formation can appear under more than one spelling across regions; filters on this column match exactly. Part of the primary key.
zone	string	yes	Landing zone within the formation: an attribute, not part of the key. Where multiple records exist for a (well, formation) pair, carries the shallowest record's zone. NULL = formation-level top with no zone detail.
formation_id	string	yes	Canonical stratigraphic-unit identifier: the join key to the formations register. NULL for formation names not yet mapped to the registry.
top_tvd	int32	yes	True vertical depth to the formation top, in feet: the shallowest value when multiple sources report. Sourced from completion-report formation lists. NULL when the source reports only a measured depth we have not converted: no as-drilled survey coverage exists at that depth (top_md still carries the reported depth).
top_md	int32	yes	Measured depth to the formation top, in feet. NULL when the source reports only TVD (the common case in Texas).
top_tvdss	int32	yes	Subsea depth of the top, in feet: elevation_kb minus top_tvd. Negative = below sea level. NULL when elevation_kb or top_tvd is unavailable. The elevation-normalized depth our formation surfaces are built from.
top_tvd_source	string	yes	Where top_tvd came from: reported = the operator-reported value, either confirmed by the well's directional survey within 50 ft or with no survey to check against; survey = the operator value disagreed with the survey by more than 50 ft and was replaced by the survey-interpolated depth at top_md. survey_filled = the source reported only a measured depth; the value is the survey-interpolated true vertical depth at that measured depth. NULL, together with top_tvd, where the source reported only a measured depth and no conversion exists: we know the measured depth (top_md) and genuinely do not know the true vertical depth. Values: reported · survey · survey_filled.
pick_source	string	yes	Who authored this formation pick: operator_report = the operator's own filed formation list (completion reports and well files); regulator_log_pick = the regulator's or geological survey's own interpretation of well logs. Empty where the pick's authorship is not yet classified. Values: operator_report · regulator_log_pick.
base_tvd	int32	yes	Depth of the formation's base (bottom boundary) at this well, true vertical depth in feet, from operator picks explicitly marked as the base (e.g. 'BASE AUSTIN CHALK'). NULL when no base pick was reported; most wells report only the top.
base_md	int32	yes	Measured depth along the wellbore of the formation's base pick, in feet. NULL when no base pick was reported.
base_tvdss	int32	yes	The formation's base in true vertical depth subsea, feet, same datum convention as top_tvdss. NULL when no base pick was reported.
elevation_kb	int32	yes	Surface elevation (kelly bushing datum), in feet, copied from the well register so subsea depth can be recomputed. NULL = elevation unknown.
latitude	float64	yes	Surface hole latitude (WGS84), copied from the well register for spatial queries.
longitude	float64	yes	Surface hole longitude (WGS84), copied from the well register.

Region-specific columns

Extra columns a single region's source adds.

wy (2 columns)

Column	Type	Description
source	string
top_md_method	string

How these numbers are built is on methodology; the machine twin of this page is data-dictionary.json.