TEXAS · WELLS · ATASCOSA COUNTY · R. MAY B LEASE · API 42-013-34543 · DISTRICT 01

R. May B #1H

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Atascosa County · Eagleville (Eagle Ford-1) field · Producing  · Horizontal

R. May B #1H (API 42-013-34543) is a horizontal well in Atascosa County operated by Marathon Oil EF LLC, completed November 18, 2023 and listed as producing on the RRC schedule.

The RRC has issued 2 drilling permits between 2012 and 2014, permitted to 11,014 ft.

Completion filings report 4 formation tops, including Anacacho, Ancacho, Austin Chalk, Eagle Ford.

Its lease has reported 5.76M barrels of oil and 7.27M mcf of gas since September 2012, last reporting volume in April 2026. The lease carries 28 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 Apr 2026
Latest permitMarathon Oil EF LLCJan 14, 2014
11,014
total depth, ft
2
permits on file
Jan 14, 2014
last permit issued
Nov 18, 2023
completed
5.76M
cumulative oil, bbl
7.27M
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Sep 2012 THROUGH Apr 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Nov 18, 2023
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; they carry 28 wells in total, so volumes are shared.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
R. May B O-1-16361Eagleville (Eagle Ford-1)Marathon Oil EF LLC285.76M7.27MSep 2012 – Apr 2026

Oil, barrels lease total

Last 12 months 87,951 · prior 12 137,851(-36%)

05K10K15K202420252026

Gas, mcf lease total

Last 12 months 81,921 · prior 12 143,197(-43%)

010K20K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCSep 2012 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
776424-99RecompletionMarathon Oil EF LLCDec 31, 2013Jan 14, 2014Jul 16, 201218,456
742505-99DrillMarathon Oil EF LLCJun 8, 2012Jun 18, 2012Jul 16, 201216,500

Completions

CompletedLeaseFieldOperatorStatusDepth
Nov 18, 2023R. May B O-1-16361Eagleville (Eagle Ford-1)Marathon Oil EF LLCProducing11,014
Nov 18, 2023R. May B O-1-16361Eagleville (Eagle Ford-1)Marathon Oil EF LLCProducing11,014

Formation tops

As filed on W-2/G-1. Subsea from 285 ft elevation.Download CSV →

FormationMD ftSubsea
Anacacho10,770-10,485
Ancacho10,770-10,485
Austin Chalk10,980-10,695
Eagle Ford11,079-10,794

Perforations

Perforated and open-hole intervals.

FromToType
11,91518,384Perforated
11,94518,384Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6254,40012.251,550 S
5.518,5068.753,272 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
00Mar 4, 2024Feb 8, 2024—
00May 21, 2020Jan 29, 2020—
00May 28, 2014Mar 27, 2014—
00Nov 12, 2013Sep 10, 2013—
00May 28, 2013Mar 15, 2013—
00Mar 14, 2013Jan 9, 2013Yes

Well logs

7 logs loaded from the RRC's log index, the latest received Sep 14, 2015. Density, Neutron, 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, Ancacho, Austin Chalk, Eagle Ford6 TIFF9,000 to 18,506Sep 14, 2015run Aug 8, 20125.72 + 1.37 + 1.50 + 1.02 + 0.86 + 2.34
COMBINATION: RESISTIVITY/NEUTRON/DENSITY POROSITYSpans Anacacho, Ancacho, Austin Chalk, Eagle FordTIFF4,401 to 11,420Sep 14, 2015run Jul 23, 201218.4
COMBINATION: RESISTIVITY/NEUTRON/DENSITY POROSITYSpans Ancacho, Anacacho, Austin Chalk, Eagle FordTIFF4,401 to 11,420Sep 10, 2015run Jul 23, 20124.37
RESISTIVITYSpans Ancacho, Anacacho, Austin Chalk, Eagle FordTIFF4,401 to 11,413Sep 10, 2015run Jul 23, 20127.70
RESISTIVITYSpans Ancacho, Anacacho, Austin Chalk, Eagle FordTIFF4,401 to 11,420Sep 10, 2015run Jul 23, 20121.92
RESISTIVITYSpans Anacacho, Ancacho, Austin Chalk, Eagle FordTIFF9,000 to 11,411Sep 14, 2015run Jul 22, 20121.64
RESISTIVITYSpans Ancacho, Anacacho, Austin Chalk, Eagle Ford5 TIFF9,000 to 11,411Sep 10, 2015run Jul 22, 20120.89 + 0.53 + 0.79 + 1.61 + 0.64

"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/01334543, documented in the API reference.