HALFMANN 4

Oil · District 08 · Lease #28427

Operator: SUNDOWN ENERGY LP

Fields: DEWEY LAKE, S. (STRAWN)

Cum Oil

40k BBL

Cum Gas

371k MCF

casinghead

Wells

2

Production

1993-01 — 2021-03

Peak Month

1996-09

Production History

Cum Oil: 40,171 BBL Cum Gas: 371,350 MCF

RRC production reported through Apr 2026 · recent months incomplete

Decline Curve Analysis

qi

584 BBL/mo

Di (annual)

36.0%

b-factor

0.0

EUR

19,418 BBL

R-squared

0.428

type

exponential

Operator History (from monthly production reports)

2021-02 — 2023-12 PIONEER NATURAL RES. USA, INC. 35 mo

2017-05 — 2021-01 PARSLEY ENERGY OPERATIONS, LLC 45 mo

2017-01 — 2017-04 DE OPERATING LLC 4 mo

2015-05 — 2016-12 DIAMONDBACK E&P LLC 20 mo

2005-02 — 2015-04 SUNDOWN ENERGY LP 123 mo

2002-07 — 2005-01 JETTA OPERATING COMPANY, INC. 31 mo

2001-07 — 2002-06 DEVON ENERGY PRODUCTION CO, L.P. 12 mo

1998-01 — 2001-06 CONCHO RESOURCES INC. 42 mo

1997-02 — 1997-12 COSTILLA ENERGY, INC. 11 mo

1993-01 — 1997-01 COSTILLA PETROLEUM CORPORATION 49 mo

Wells (2)

WELL#	API	OPERATOR	PERMITS	DEPTH	LAST_ISSUED
1	42-173-31435	PIONEER NATURAL RES. USA, INC.	2	10,300	2009-09-08
2	42-173-31514	PIONEER NATURAL RES. USA INC.	1	10,200	1983-11-23

HALFMANN 4

Production HistoryBeta Production data is a work in progress — still being validated against RRC filings. Spot something off or have questions? [email protected]

Decline Curve Analysis

Operator History (from monthly production reports)

Wells (2)

Production History