COOPER 357

Oil · District 10 · Lease #7840

Operator: HIGHMARK ENERGY OPERATING, LLC

Cum Oil

177k BBL

Cum Gas

1.4M MCF

casinghead

Wells

2

Production

2008-02 — 2026-04

Peak Month

2009-01

Production History

Cum Oil: 177,252 BBL Cum Gas: 1,430,039 MCF

RRC production reported through Apr 2026 · recent months incomplete

Decline Curve Analysis

qi

4,487 BBL/mo

Di (annual)

50.3%

b-factor

0.3

EUR

151,900 BBL

R-squared

0.780

type

hyperbolic

Operator History (from monthly production reports)

2022-02 — 2026-07 HIGHMARK ENERGY OPERATING, LLC 54 mo
2008-02 — 2022-01 EOG RESOURCES, INC. 168 mo

Wells (2)

WELL#APIOPERATORPERMITSDEPTHLAST_ISSUED
3HHIGHMARK ENERGY OPERATING, LLC19,0002008-10-04
1HHIGHMARK ENERGY OPERATING, LLC19,0002007-07-13