WALLVILLE 321

Oil · District 10 · Lease #8857

Operator: HIGHMARK ENERGY OPERATING, LLC

Cum Oil

157k BBL

Cum Gas

1.5M MCF

casinghead

Wells

2

Production

2013-01 — 2026-04

Peak Month

2013-03

Production History

Cum Oil: 156,906 BBL Cum Gas: 1,478,840 MCF

RRC production reported through Apr 2026 · recent months incomplete

Decline Curve Analysis

qi

2,856 BBL/mo

Di (annual)

52.2%

b-factor

0.6

EUR

138,927 BBL

R-squared

0.629

type

hyperbolic

Operator History (from monthly production reports)

2022-02 — 2026-07 HIGHMARK ENERGY OPERATING, LLC 54 mo
2013-01 — 2022-01 EOG RESOURCES, INC. 109 mo

Wells (2)

WELL#APIOPERATORPERMITSDEPTHLAST_ISSUED
3HHIGHMARK ENERGY OPERATING, LLC19,0002013-03-07
2HHIGHMARK ENERGY OPERATING, LLC19,0002012-11-05