TEXAS · WELLS · KARNES COUNTY · HIERHOLZER-HEDTKE UNIT LEASE · API 42-255-32582 · DISTRICT 02

Hierholzer-Hedtke Unit #1H

Shut in

Karnes County · Eagleville (Eagle Ford-2) field · Shut In  · Horizontal

Hierholzer-Hedtke Unit #1H (API 42-255-32582) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed September 24, 2021 and listed as shut in on the RRC schedule, shut in June 1, 2025.

The RRC has issued one drilling permit, issued June 14, 2012, permitted to 11,123 ft.

Completion filings report 3 formation tops, including Anacacho, Austin Chalk, Eagle Ford.

Its lease has reported 658K barrels of oil and 778K mcf of gas since September 2012, last reporting volume in January 2026. The lease carries 3 wells, so these are lease totals, not this well alone.

Operator of record

Marathon Oil EF LLC

Based in
Houston, TX
P-5 status
Active (A)
P-5 last filed
Sep 26, 2025
Permits on file
3,191
Phone
(832) 486-2737

SOURCE · RRC EWA WELLBORE SCHEDULE

What each RRC source says

Wellbore scheduleMarathon Oil EF LLC
Production reportsMarathon Oil EF LLCthrough Jan 2026
Latest permitMarathon Oil EF LLCJun 14, 2012
11,123
total depth, ft
1
permits on file
Jun 14, 2012
last permit issued
Sep 24, 2021
completed
658K
cumulative oil, bbl
778K
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Sep 2012 THROUGH Jan 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Sep 24, 2021
Shut in
Jun 1, 2025
Plugged
—

Operator's P-5 on the schedule: Active – Extension (X)

Surface location

No coordinates on the permit record yet. The RRC's GIS record usually lands within days of issuance; historical master-file permits never carry one.

Lease production

PDQ LEASE REPORTS · REPORTED THROUGH APR 2026

Texas reports oil by lease, not by well. These are the lease this well is completed on; they carry 3 wells in total, so volumes are shared.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Hierholzer-Hedtke Unit O-2-10307Eagleville (Eagle Ford-2)Marathon Oil EF LLC3658K778KSep 2012 – Jan 2026

Oil, barrels lease total

Last 12 months 6,397 · prior 12 17,163(-63%)

01K2K3K202420252026

Gas, mcf lease total

Last 12 months 5,303 · prior 12 12,355(-57%)

02K4K202420252026

Chain of custody

Every operator that reported production on this well's lease, in order.

  1. 1Marathon Oil EF LLCSep 2012 → Oct 2025

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
742192-99DrillMarathon Oil EF LLCJun 5, 2012Jun 14, 2012Jul 18, 201217,500

Completions

CompletedLeaseFieldOperatorStatusDepth
Sep 24, 2021Hierholzer-Hedtke Unit O-2-10307Eagleville (Eagle Ford-2)Marathon Oil EF LLCShut In · shut in Jun 1, 202511,123

Formation tops

As filed on W-2/G-1. Subsea from 461 ft elevation.Download CSV →

FormationMD ftSubsea
Anacacho10,941-10,480
Austin Chalk11,085-10,624
Eagle Ford11,279-10,818

Perforations

Perforated and open-hole intervals.

FromToType
11,48019,117Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6255,71212.251,726 S
5.519,2378.752,020 S

Completion filings

W-2 and G-1 reports on record in the RRC wellbore file, newest first. The suffix identifies the wellbore or completion event. The record date is the RRC's own date on the record, not the day the report was filed: 462,034 of the state's filings carry 1984-01-12. About these reports →

SuffixRRC record dateW-2 / G-1 dateLogs referenced
00Nov 18, 2021Oct 14, 2021—
00Mar 19, 2013Dec 21, 2012Yes
00Mar 6, 2013Dec 19, 2012—
00Feb 27, 2013Nov 27, 2012Yes

Well logs

1 log loaded from the RRC's log index, the latest received Oct 6, 2015. Resistivity. These are the logs loaded into Petrora from the Railroad Commission's inventories, not necessarily every log run on the well. The RRC holds the files; each opens from its log search for the well. The kind is the RRC's description of the log; the interval is the one filed for it.

Open the RRC's log search for this well ↗
Logas describedFiles Intervalft, as filedDatereceivedSizeMB
RESISTIVITYSpans Anacacho, Austin Chalk, Eagle Ford6 TIFF5,712 to 19,428Oct 6, 2015run Aug 2, 20120.26 + 1.05 + 0.62 + 1.16 + 2.77 + 0.42

"Spans" is by this well's own filed formation tops: a formation runs from its top to the next deeper top filed, and the deepest runs to the bottom of the log. Depths are measured along the wellbore, so on a horizontal the lateral counts in the formation it was landed in.

Find logs withinmiles of this well:List →Map →

Search the well logs loaded into Petrora →

The source documents

Petrora holds the structured record. The scanned filings live at the RRC; these links open its search already filled in for this API.

The logs loaded for this well are under Well logs, with the RRC's log search for it.

About this data

Permits from the RRC OGA049M master and daily daf420 files; wellbore and operator of record from the EWA schedule, weekly; completions, formation tops, casing, and perforations from the dbf900 wellbore file; production from PDQ lease reports, which lag two to three months; injection from UIC permits, H-10 reports, and TexNet daily volumes; earthquakes from the TexNet catalog.

New to these records? How to read a well page · API numbers · completion reports and tops · why production is by lease

Developers: this page as JSON is GET /v1/data/wells/25532582, documented in the API reference.