TEXAS · WELLS · KARNES COUNTY · MAY B UNIT AC LEASE · API 42-255-34662 · DISTRICT 02

May B Unit AC #4H

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

May B Unit AC #4H (API 42-255-34662) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed November 24, 2015 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued July 6, 2015, permitted to 12,186 ft.

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

Its lease has reported 101K barrels of oil and 770K mcf of gas since November 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 LLCJul 6, 2015
12,186
total depth, ft
1
permits on file
Jul 6, 2015
last permit issued
Nov 24, 2015
completed
101K
cumulative oil, bbl
770K
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Nov 2015 THROUGH Apr 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Nov 24, 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-2-280084Sugarkane (Austin Chalk)Marathon Oil EF LLC1101K770KNov 2015 – Apr 2026

Gas, mcf lease total

Last 12 months 6,223 · prior 12 2,632(+136%)

05001K1.5K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCNov 2015 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
807864-99DrillMarathon Oil EF LLCJun 26, 2015Jul 6, 2015Sep 6, 201518,200

Completions

CompletedLeaseFieldOperatorStatusDepth
Nov 24, 2015May B Unit AC G-2-280084Sugarkane (Austin Chalk)Marathon Oil EF LLCProducing12,186

Formation tops

As filed on W-2/G-1. Subsea from 480 ft elevation.Download CSV →

FormationMD ftSubsea
FrioFRIO - DISPOSAL1,500-1,020
YeguaYEGUA - DISPOSAL2,027-1,547
Queen City4,425-3,945
Reklaw4,822-4,342
Carrizo5,412-4,932
WilcoxWILCOX - DISPOSAL6,585-6,105
Austin ChalkAUSTIN CHALK - H2S12,276-11,796
Eagle FordEAGLE FORD - H2S——
EdwardsEDWARDS - H2S——
SligoSLIGO - H2S——

Perforations

Perforated and open-hole intervals.

FromToType
12,52617,195Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6255,61612.251,540 S
5.517,3058.52,075 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
00Jun 8, 2016Dec 21, 2015Yes

Well logs

1 log loaded from the RRC's log index, 1 of it with a digital LAS file, the latest received Oct 12, 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 Wilcox, Austin ChalkLAS + TIFF11,500 to 17,265Oct 12, 20180.73 + 2.60

"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/25534662, documented in the API reference.