TEXAS · WELLS · KARNES COUNTY · MOBIL UNIT B AC LEASE · API 42-255-34277 · DISTRICT 02

Mobil Unit B AC #4H

Shut in

Karnes County · Sugarkane (Austin Chalk) field · Temp Abandoned  · Horizontal

Mobil Unit B AC #4H (API 42-255-34277) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed April 10, 2015 and listed as temp abandoned on the RRC schedule, shut in July 1, 2023.

The RRC has issued one drilling permit, issued October 28, 2014, permitted to 11,976 ft.

Completion filings report 10 formation tops, including Yegua, Queen City, Reklaw, Carrizo.

Its lease has reported 136K barrels of oil and 1.11M mcf of gas since April 2015, last reporting volume in December 2025.

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 Dec 2025
Latest permitMarathon Oil EF LLCOct 28, 2014
11,976
total depth, ft
1
permits on file
Oct 28, 2014
last permit issued
Apr 10, 2015
completed
136K
cumulative oil, bbl
1.11M
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Apr 2015 THROUGH Dec 2025

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Apr 10, 2015
Shut in
Jul 1, 2023
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; this well is the only one on it.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Mobil Unit B AC G-2-279744Sugarkane (Austin Chalk)Marathon Oil EF LLC1136K1.11MApr 2015 – Dec 2025

Gas, mcf lease total

Last 12 months 429 · prior 12 0

0200400600202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCApr 2015 → Dec 2025

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
798633-99DrillMarathon Oil EF LLCOct 19, 2014Oct 28, 2014Dec 15, 201418,500

Completions

CompletedLeaseFieldOperatorStatusDepth
Apr 10, 2015Mobil Unit B AC G-2-279744Sugarkane (Austin Chalk)Marathon Oil EF LLCTemp Abandoned · shut in Jul 1, 202311,976

Formation tops

As filed on W-2/G-1. Subsea from 430 ft elevation.Download CSV →

FormationMD ftSubsea
YeguaYEGUA - DISPOSAL1,883-1,453
Queen City4,183-3,753
Reklaw4,640-4,210
Carrizo5,297-4,867
WilcoxWILCOX - DISPOSAL6,530-6,100
Austin ChalkAUSTIN CHALK - H2S12,082-11,652
Eagle FordEAGLE FORD - H2S——
EdwardsEDWARDS - H2S——
FrioFRIO - DISPOSAL——
SligoSLIGO - H2S——

Perforations

Perforated and open-hole intervals.

FromToType
12,41018,038Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6256,17112.252,309 S
5.518,1348.52,954 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
00Apr 26, 2016Jul 17, 2015Yes

Well logs

1 log loaded from the RRC's log index, 1 of it with a digital LAS file, the latest received Jan 9, 2018. Gamma ray. 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
Gamma RaySpans Carrizo, Wilcox, Austin ChalkLAS + TIFF6,169 to 18,122Jan 9, 20181.70 + 37.2

"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/25534277, documented in the API reference.