TEXAS · WELLS · KARNES COUNTY · MAY B UNIT AC LEASE · API 42-255-34012 · DISTRICT 02

May B Unit AC #1H

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Karnes County · Sugarkane (Austin Chalk) field · Producing  · Horizontal

May B Unit AC #1H (API 42-255-34012) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed January 20, 2015 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued August 15, 2014, permitted to 12,171 ft.

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

Its lease has reported 127K barrels of oil and 824K mcf of gas since January 2015, last reporting volume in April 2026.

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 Apr 2026
Latest permitMarathon Oil EF LLCAug 15, 2014
12,171
total depth, ft
1
permits on file
Aug 15, 2014
last permit issued
Jan 20, 2015
completed
127K
cumulative oil, bbl
824K
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Jan 2015 THROUGH Apr 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Jan 20, 2015
Shut in
—
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
May B Unit AC G-2-279244Sugarkane (Austin Chalk)Marathon Oil EF LLC1127K824KJan 2015 – Apr 2026

Gas, mcf lease total

Last 12 months 8,222 · prior 12 24,346(-66%)

02K4K6K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCJan 2015 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
791379-99DrillMarathon Oil EF LLCJul 10, 2014Aug 15, 2014Sep 18, 201418,000

Completions

CompletedLeaseFieldOperatorStatusDepth
Jan 20, 2015May B Unit AC G-2-279244Sugarkane (Austin Chalk)Marathon Oil EF LLCProducing12,171

Formation tops

As filed on W-2/G-1. Subsea from 470 ft elevation.Download CSV →

FormationMD ftSubsea
FrioFRIO - DISPOSAL3,200-2,730
Carrizo3,450-2,980
Reklaw3,960-3,490
YeguaYEGUA - DISPOSAL4,000-3,530
WilcoxWILCOX - DISPOSAL4,980-4,510
Queen City6,440-5,970
Austin ChalkAUSTIN CHALK - H2S12,223-11,753
Eagle FordEAGLE FORD - H2S——
EdwardsEDWARDS - H2S——
SligoSLIGO - H2S——

Perforations

Perforated and open-hole intervals.

FromToType
12,58516,200Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6254,95512.251,715 S
5.516,3178.52,753 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
00Feb 26, 2016May 1, 2015Yes

Well logs

1 log loaded from the RRC's log index, 1 of it with a digital LAS file, the latest received Nov 16, 2017. 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 Yegua, Wilcox, Queen City, Austin ChalkLAS + TIFF4,950 to 16,291Nov 16, 20171.81 + 34.8

"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/25534012, documented in the API reference.