WELL · 42-255-37694 · DISTRICT 2

Turnbull E-F-Kowalik SA1 #1H

Y

Karnes County · Eagleville (Eagle Ford-2) field · Producing  · Horizontal

Turnbull E-F-Kowalik Sa1 #1H (API 42-255-37694) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed October 11, 2023 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit, issued February 1, 2023, permitted to 22,000 ft.

Completion filings report 11 formation tops, including Cook Mountain, Queen City, Reklaw, Carrizo.

Its lease has reported 194K barrels of oil and 700K mcf of gas since July 2023, last reporting in July 2026.

Operator of record

Marathon Oil EF LLC

Houston, TX · P-5 Y, filed Aug 4, 2025 · 3,191 permits on file · (800) 332-9449

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 LLCFeb 1, 2023
22,000
total depth, ft
1
permits on file
Feb 1, 2023
last permit issued
Oct 11, 2023
completed
194K
cumulative oil, bbl
700K
cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Jul 2023 THROUGH Jul 2026

Regulatory status · RRC wellbore file

Schedule
ON SCHEDULE
Completed
Oct 11, 2023
Shut in
—
Plugged
—

Operator's P-5 on the schedule: Active

Surface location

28.808940, -98.040333

OpenStreetMap → ·  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 lease this well is completed on; this well is the only one on it.Why →

LeaseFieldReporting operatorWellsOil, bblGas, mcfReported
Turnbull E-F-Kowalik SA1 O-2-12661Eagleville (Eagle Ford-2)Marathon Oil EF LLC1194K700KJul 2023 – Jul 2026

Oil, barrels lease total

Last 12 months 19,285 · prior 12 42,437(-55%)

010K20K30K202420252026

Gas, mcf lease total

Last 12 months 190,208 · prior 12 236,853(-20%)

020K40K202420252026

Chain of custody

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

  1. 1Marathon Oil EF LLCJul 2023 → Apr 2026

Permits

PermitTypeOperatorReceivedIssuedSpudDepth
887596-99DrillMarathon Oil EF LLCJan 24, 2023Feb 1, 2023Mar 4, 202322,000

Completions

CompletedLeaseFieldOperatorStatusDepth
—— O-2-12661————

Formation tops

As filed on W-2/G-1. Subsea from 434 ft elevation.Download CSV →

FormationMD ftSubsea
Cook Mountain2,479-2,045
Queen City3,350-2,916
Reklaw3,936-3,502
Carrizo4,493-4,059
WilcoxWILCOX - DISPOSAL4,569-4,135
Austin ChalkAUSTIN CHALK - H2S11,188-10,754
Eagle FordEAGLE FORD - H2S11,364-10,930
EdwardsEDWARDS - H2S——
FrioFRIO - DISPOSAL——
SligoSLIGO - H2S——
YeguaYEGUA - DISPOSAL——

Perforations

Perforated and open-hole intervals.

FromToType
11,53819,289Perforated

Casing

Strings as reported, shallowest first.

Casing inSet atHole inCement
9.6255,68312.251,386 S
619,2898.753,093 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
00Mar 7, 2024Feb 5, 2024—
00Oct 10, 2023Sep 11, 2023Yes

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 neighbours, subsea-aligned so they line up regardless of surface terrain.

Open the cross-section →

Turnbull E-F-Kowalik SA242-255-37695

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

Cook Mountain2,479-2,045
Sparta3,074-2,640
Queen City3,350-2,916
Reklaw3,936-3,502
Carrizo4,493-4,059
Wilcox4,569-4,135
Anacacho11,029-10,595
Austin Chalk11,182-10,748

13 TOPS · FIRST 8

Turnbull Unit F42-255-37699

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

Cook Mountain2,479-2,045
Sparta3,074-2,640
Queen City3,350-2,916
Reklaw3,936-3,502
Carrizo4,493-4,059
Wilcox4,569-4,135
Anacacho11,060-10,626
Austin Chalk11,196-10,762

12 TOPS · FIRST 8

Turnbull Unit F42-255-37698

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

Cook Mountain2,479-2,045
Sparta3,074-2,640
Queen City3,350-2,916
Reklaw3,936-3,502
Carrizo4,493-4,059
Wilcox4,569-4,135
Anacacho11,046-10,612
Austin Chalk11,197-10,763

10 TOPS · FIRST 8

Coy City Ranch Unit B42-255-37697

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

Queen City3,350-2,916
Reklaw3,936-3,502
Carrizo4,493-4,059
Wilcox4,569-4,135
Austin Chalk11,188-10,754
Eagle Ford11,377-10,943
Yegua—
Edwards—

10 TOPS · FIRST 8

Coy City Ranch Unit B42-255-37696

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

Queen City3,350-2,916
Reklaw3,936-3,502
Carrizo4,493-4,059
Wilcox4,569-4,135
Austin Chalk11,195-10,761
Eagle Ford11,370-10,936
Sligo—
Yegua—

10 TOPS · FIRST 8

Turnbull Unit E42-255-36641

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

Yegua1,409-996
Queen City3,547-3,134
Reklaw4,274-3,861
Carrizo4,597-4,184
Wilcox6,191-5,778
Austin Chalk11,153-10,740
Eagle Ford11,329-10,916
Sligo—

10 TOPS · FIRST 8

Turnbull Unit E42-255-36642

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

Yegua1,409-996
Queen City3,547-3,134
Reklaw4,274-3,861
Carrizo4,597-4,184
Wilcox6,191-5,778
Austin Chalk11,168-10,755
Eagle Ford11,332-10,919
Frio—

10 TOPS · FIRST 8

Turnbull Unit E42-255-36640

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

Yegua1,409-995
Queen City3,547-3,133
Reklaw4,272-3,858
Carrizo4,597-4,183
Wilcox6,191-5,777
Austin Chalk11,139-10,725
Eagle Ford11,319-10,905
Frio—

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/25537694, documented in the API reference.