SWINK 391

Oil · District 10 · Lease #8041

Operator: HIGHMARK ENERGY OPERATING, LLC

Cum Oil

89k BBL

Cum Gas

446k MCF

casinghead

Wells

1

Production

2009-08 — 2026-04

Peak Month

2010-05

Production History

Cum Oil: 89,176 BBL Cum Gas: 445,691 MCF

RRC production reported through Apr 2026 · recent months incomplete

Decline Curve Analysis

qi

3,355 BBL/mo

Di (annual)

74.5%

b-factor

0.4

EUR

88,608 BBL

R-squared

0.860

type

hyperbolic

Operator History (from monthly production reports)

2022-02 — 2026-07 HIGHMARK ENERGY OPERATING, LLC 54 mo
2009-08 — 2022-01 EOG RESOURCES, INC. 150 mo

Wells (1)

WELL#APIOPERATORPERMITSDEPTHLAST_ISSUED
1HHIGHMARK ENERGY OPERATING, LLC29,0002009-05-21