TEXAS · WELLS · KARNES COUNTY · YOSKO BORGFELD-YOSKO UNIT SA LEASE · API 42-255-36919 · DISTRICT 02

Yosko Borgfeld-Yosko Unit SA #1H

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

Yosko Borgfeld-Yosko Unit SA #1H (API 42-255-36919) is a horizontal well in Karnes County operated by Marathon Oil EF LLC, completed October 6, 2021 and listed as producing on the RRC schedule.

The RRC has issued one drilling permit (amended once), issued April 6, 2020, permitted to 11,975 ft.

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

Its lease has reported 386K barrels of oil and 703K mcf of gas since July 2020, 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

Watch this operator Watch Karnes County

SOURCE · RRC EWA WELLBORE SCHEDULE

What each RRC source says

Wellbore schedule	Marathon Oil EF LLC
Production reports	Marathon Oil EF LLCthrough Apr 2026
Latest permit	Marathon Oil EF LLCApr 6, 2020

11,975: total depth, ft
2: permits on file
Apr 6, 2020: last permit issued
Oct 6, 2021: completed
386K: cumulative oil, bbl
703K: cumulative gas, mcf

PRODUCTION FROM PDQ LEASE REPORTS · Apr 2021 THROUGH Apr 2026

Regulatory status · RRC wellbore file

Schedule: ON SCHEDULE
Completed: Oct 6, 2021
Shut in: —
Plugged: —

Operator's P-5 on the schedule: Active – Extension (X)

Surface location

28.844532, -97.946102 NAD27, as filed

28.844789, -97.946383 WGS84

Google Maps ↗

Permit surface location from the RRC GIS record, referenced to NAD27 as the RRC files it; the WGS84 pair is the same point through NOAA's NADCON grid, and the map link uses it, in Karnes County.

Wells nearby

Withinmiles

Every well with a location on file around this one, in any state, nearest first.

Loading the wells nearby…

Open the full map →

Texas locations come from drilling permits, so most older Texas wells have none and are not listed.

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 →

Lease	Field	Reporting operator	Wells	Oil, bbl	Gas, mcf	Reported
Yosko Borgfeld-Yosko Unit SA O-2-12081	Eagleville (Eagle Ford-2)	Marathon Oil EF LLC	1	386K	703K	Jul 2020 – Apr 2026

Oil, barrels lease total

Last 12 months 22,421 · prior 12 28,842(-22%)

Gas, mcf lease total

Last 12 months 54,558 · prior 12 94,626(-42%)

Chain of custody

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

1Marathon Oil EF LLCApr 2021 → Apr 2026

Permits

Permit	Type	Operator	Received	Issued	Spud	Depth
863089-98	Drill	Marathon Oil EF LLC	Sep 2, 2020	Apr 6, 2020	Jul 23, 2020	22,000
863089-99	Drill	Marathon Oil EF LLC	Mar 26, 2020	Apr 6, 2020	Jul 23, 2020	22,000

Completions

Completed	Lease	Field	Operator	Status	Depth
Oct 6, 2021	Yosko Borgfeld-Yosko Unit SA O-2-12081	Eagleville (Eagle Ford-2)	Marathon Oil EF LLC	Producing	11,975

Formation tops

As filed on W-2/G-1. Subsea from 343 ft elevation.Download CSV →

Formation	MD ft	Subsea
YeguaYEGUA - DISPOSAL	1,855	-1,512
Queen City	3,835	-3,492
Reklaw	4,375	-4,032
Carrizo	4,925	-4,582
WilcoxWILCOX - DISPOSAL	5,055	-4,712
Austin ChalkAUSTIN CHALK - H2S	11,897	-11,554
Eagle FordEAGLE FORD - H2S	12,079	-11,736
EdwardsEDWARDS - H2S	—	—
FrioFRIO - DISPOSAL	—	—
SligoSLIGO - H2S	—	—

Perforations

Perforated and open-hole intervals.

From	To	Type
12,471	19,226	Perforated

Casing

Strings as reported, shallowest first.

Casing in	Set at	Hole in	Cement
9.625	5,658	12.25	1,643 S
5.5	19,226	8.75	2,895 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 →

RRC record date	W-2 / G-1 date	Logs referenced
Nov 15, 2021	Nov 4, 2021	Yes
Jun 8, 2021	May 20, 2021	—
Nov 6, 2020	Oct 30, 2020	Yes

Well logs

1 log loaded from the RRC's log index, the latest received Sep 17, 2024. 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 described	Files	Intervalft, as filed	Datereceived	SizeMB
Gamma RaySpans Yegua, Queen City, Reklaw, Carrizo, Wilcox, Austin Chalk, Eagle Ford	TIFF	0 to 19,244	Sep 17, 2024	2.64

"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.

Wellbore filings for 42-255-36919 → W-2, G-1, plugging reports, as PDFs
Completion packets for 42-255-36919 → scanned completion filings

The logs loaded for this well are under Well logs, with the RRC's log search for it.

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 →

Yosko Borgfeld Unit42-255-36917

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

Yegua	1,855	-1,512
Queen City	3,835	-3,492
Reklaw	4,375	-4,032
Carrizo	4,925	-4,582
Wilcox	5,055	-4,712
Austin Chalk	11,737	-11,394
Eagle Ford	12,076	-11,733
Sligo	—

10 TOPS · FIRST 8

Yosko Borgfeld Unit42-255-36918

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

Yegua	1,855	-1,512
Queen City	3,835	-3,492
Reklaw	4,375	-4,032
Carrizo	4,925	-4,582
Wilcox	5,055	-4,712
Austin Chalk	11,878	-11,535
Eagle Ford	11,931	-11,588
Frio	—

10 TOPS · FIRST 8

Yosko Borgfeld Unit42-255-36916

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

Yegua	1,855	-1,512
Queen City	3,835	-3,492
Reklaw	4,375	-4,032
Carrizo	4,925	-4,582
Wilcox	5,055	-4,712
Austin Chalk	11,864	-11,521
Eagle Ford	12,048	-11,705
Edwards	—

10 TOPS · FIRST 8

Brysch Jonas-Yosko Borgfeld SA42-255-36920

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

Yegua	1,855	-1,512
Queen City	3,835	-3,492
Reklaw	4,375	-4,032
Carrizo	4,925	-4,582
Wilcox	5,055	-4,712
Austin Chalk	11,842	-11,499
Eagle Ford	12,028	-11,685
Frio	—

10 TOPS · FIRST 8

Chapman-Franke-Murphy-Kotara SA42-255-37630

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

Queen City	3,913	-3,585
Reklaw	4,454	-4,126
Carrizo	4,995	-4,667
Wilcox	5,074	-4,746
Austin Chalk	11,951	-11,623
Eagle Ford	12,149	-11,821
Frio	—
Edwards	—

10 TOPS · FIRST 8

Chapman Rogers-Franke SA42-255-37631

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

Queen City	3,913	-3,585
Reklaw	4,454	-4,126
Carrizo	4,995	-4,667
Wilcox	5,074	-4,746
Austin Chalk	12,019	-11,691
Eagle Ford	12,156	-11,828
Edwards	—
Frio	—

10 TOPS · FIRST 8

Zaeske-Eckols-Franke SA42-255-37632

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

Sparta	3,609	-3,281
Queen City	3,913	-3,585
Reklaw	4,454	-4,126
Carrizo	4,995	-4,667
Wilcox	5,074	-4,746
Anacacho	11,817	-11,489
Austin Chalk	11,968	-11,640
Eagle Ford	12,157	-11,829

12 TOPS · FIRST 8

Franke Unit42-255-37871

1.7 KM · Devon Energy Production Co, L.P. · Section with this well →

Frio	1,894	-1,569
Yegua	2,881	-2,556
Queen City	3,978	-3,653
Reklaw	4,413	-4,088
Carrizo	4,942	-4,617
Wilcox	5,218	-4,893
Austin Chalk	12,131	-11,806
Eagle Ford	12,286	-11,961

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/25536919, documented in the API reference.