SHAMROCK -4-

Oil · District 08 · Lease #30755

Operator: NORTHSTAR OPERATING COMPANY

Cum Oil

2k BBL

Cum Gas

87k MCF

casinghead

Wells

1

Production

1993-01 — 2009-04

Peak Month

2002-07

Production History

Cum Oil: 1,527 BBL Cum Gas: 87,255 MCF

RRC production reported through Apr 2026 · recent months incomplete

Decline Curve Analysis

qi

26 BBL/mo

Di (annual)

23.7%

b-factor

0.0

EUR

1,274 BBL

R-squared

0.525

type

exponential

Operator History (from monthly production reports)

2004-01 — 2010-02 NORTHSTAR OPERATING COMPANY 74 mo
1996-02 — 2003-12 LIMARK CORPORATION 95 mo
1993-01 — 1996-01 MWJ PRODUCING COMPANY 37 mo

Wells (1)

WELL#APIOPERATORPERMITSDEPTHLAST_ISSUED
1PIONEER NATURAL RES. USA INC.110,5001984-12-18