WELL · 42-255-35509 · DISTRICT 2

Kowalik 228-1R #10H

N

Karnes County · Sugarkane (Eagle Ford) field  · Horizontal

Kowalik 228-1r #10H (API 42-255-35509) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed October 22, 2018.

The RRC has issued one drilling permit, issued June 21, 2017, permitted to 22,130 ft.

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

Its 2 leases have reported 799K barrels of oil and 4.42M mcf of gas since September 2014, last reporting in July 2026. The leases carry 11 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 LLCJun 21, 2017
22,130
total depth, ft
1
permits on file
Jun 21, 2017
last permit issued
Oct 22, 2018
completed
799K
cumulative oil, bbl
4.42M
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Sep 2014 THROUGH Jul 2026

Regulatory status · RRC wellbore file

Schedule
OFF SCHEDULE
Completed
Oct 22, 2018
Shut in
—
Plugged
—

Surface location

28.770214, -98.010917

Google Maps ↗

Permit surface location from the RRC GIS record, in Karnes County.

Lease production

PDQ LEASE REPORTS · REPORTED THROUGH APR 2026

Texas reports oil by lease, not by well. These are the 2 leases this well is completed on; they carry 11 wells in total, so volumes are shared.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Kowalik 228-1R G-2-294676Sugarkane (Eagle Ford)Marathon Oil EF LLC101.84MOct 2018 – Jul 2026
Kowalik 228-1R O-2-10909Sugarkane (Eagle Ford)Marathon Oil EF LLC10799K2.58MSep 2014 – Jul 2026

Gas, mcf lease total

Last 12 months 101,791 · prior 12 111,360(-9%)

010K20K30K202420252026

Oil, barrels lease total

Last 12 months 11,375 · prior 12 6,529(+74%)

01K2K3K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCSep 2014 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
827449-99DrillMarathon Oil EF LLCJun 5, 2017Jun 21, 2017Sep 18, 201822,130

Completions

CompletedLeaseFieldOperatorStatusDepth
—— G-2-294676————
—— O-2-10909————

Formation tops

As filed on W-2/G-1. Subsea from 420 ft elevation.Download CSV →

FormationMD ftSubsea
YeguaYEGUA - DISPOSAL1,802-1,382
Queen City3,948-3,528
Reklaw4,416-3,996
Carrizo4,906-4,486
Austin ChalkAUSTIN CHALK - H2S11,838-11,418
Eagle FordEAGLE FORD - H2S11,935-11,515
EdwardsEDWARDS - H2S——
FrioFRIO - DISPOSAL——
SligoSLIGO - H2S——
WilcoxWILCOX - DISPOSAL——

Perforations

Perforated and open-hole intervals.

FromToType
12,09820,930Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6256,04412.251,950 S
5.521,0388.753,080 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. About these reports →

SuffixFiledW-2 / G-1 dateLogs referenced
00Jun 2, 2023Apr 12, 2023Yes
00Jan 30, 2019Nov 7, 2018Yes
00Oct 24, 2018Sep 7, 2018Yes

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.

Log images are in archives with no per-well link: the RRC's Neubus archive (2004 onward). then paste it into their search.

Nearby wells and their tops

NEAREST 8 LOCATED WELLS WITH TOPS · WITHIN 16 KM

Draw a cross-section

This well's tops beside its 5 nearest neighbors, subsea-aligned so they line up regardless of surface terrain.

Open the cross-section →

Kowalik 228-1R42-255-35510

0.0 KM · Marathon Oil EF LLC · Section with this well →

Yegua1,802-1,383
Queen City3,948-3,529
Reklaw4,416-3,997
Carrizo4,906-4,487
Wilcox6,461-6,042
Austin Chalk11,809-11,390
Eagle Ford11,907-11,488
Frio—

10 TOPS · FIRST 8

Kowalik 228-1R42-255-35511

0.0 KM · Marathon Oil EF LLC · Section with this well →

Yegua1,826-1,407
Queen City4,037-3,618
Reklaw4,704-4,285
Carrizo4,999-4,580
Wilcox6,461-6,042
Austin Chalk11,809-11,390
Eagle Ford11,907-11,488
Sligo—

10 TOPS · FIRST 8

Davila-Weston Henke Unit SA C42-255-37017

0.3 KM · Marathon Oil EF LLC · Section with this well →

Yegua1,667-1,235
Queen City4,065-3,633
Reklaw4,462-4,030
Carrizo5,052-4,620
Wilcox6,225-5,793
Austin Chalk11,877-11,445
Eagle Ford12,002-11,570
Edwards—

10 TOPS · FIRST 8

Davila-Weston Henke Unit SA B42-255-37016

0.3 KM · Marathon Oil EF LLC · Section with this well →

Yegua1,667-1,234
Queen City4,065-3,632
Reklaw4,462-4,029
Carrizo5,052-4,619
Wilcox6,225-5,792
Austin Chalk11,885-11,452
Eagle Ford12,003-11,570
Frio—

10 TOPS · FIRST 8

Davila-Weston Henke Unit SA A42-255-37015

0.3 KM · Marathon Oil EF LLC · Section with this well →

Yegua1,667-1,233
Queen City4,065-3,631
Reklaw4,462-4,028
Carrizo5,052-4,618
Wilcox6,225-5,791
Austin Chalk11,886-11,452
Eagle Ford12,012-11,578
Edwards—

10 TOPS · FIRST 8

Davila-Mobil a-Kennedy Unit SA42-255-37018

0.3 KM · Marathon Oil EF LLC · Section with this well →

Yegua1,667-1,232
Queen City4,065-3,630
Reklaw4,462-4,027
Carrizo5,052-4,617
Wilcox6,225-5,790
Austin Chalk11,847-11,412
Eagle Ford11,968-11,533
Edwards—

10 TOPS · FIRST 8

Davila-Graham-Kowalik SA42-255-37022

0.3 KM · Marathon Oil EF LLC · Section with this well →

Yegua1,667-1,230
Queen City4,065-3,628
Reklaw4,462-4,025
Carrizo5,052-4,615
Wilcox6,225-5,788
Austin Chalk11,923-11,486
Eagle Ford12,038-11,601
Frio—

10 TOPS · FIRST 8

Children Weston-Mobil a SA42-255-37729

0.3 KM · Marathon Oil EF LLC · Section with this well →

Queen City3,784-3,378
Reklaw4,247-3,841
Carrizo4,920-4,514
Wilcox4,992-4,586
Austin Chalk11,747-11,341
Eagle Ford11,870-11,464
Frio—
Edwards—

10 TOPS · FIRST 8

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/25535509, documented in the API reference.