< leases

COLBY, E.H. ET AL

Oil · District 03 · Lease #18825

Operator: TEXCAL ENERGY (GP) LLC

Fields: MANVEL (OLIGOCENE)

Cum Oil

194k BBL

Cum Gas

423k MCF

casinghead

Wells

1

Production

1993-01 — 2025-08

Peak Month

2014-02

Production History

Cum Oil: 193,937 BBL Cum Gas: 423,074 MCF

RRC production reported through Apr 2026 · recent months incomplete

Decline Curve Analysis

qi

1,741 BBL/mo

Di (annual)

41.1%

b-factor

0.2

EUR

63,402 BBL

R-squared

0.704

type

hyperbolic

Operator History (from monthly production reports)

2015-05 — 2026-07 DENBURY ONSHORE, LLC 135 mo
2012-10 — 2015-04 ARGENT ENERGY (US) HOLDINGS INC. 31 mo
2010-05 — 2012-09 ENERGYQUEST II, LLC 29 mo
2007-04 — 2010-04 TEXCAL ENERGY (GP) LLC 37 mo
2006-01 — 2007-03 POGO PRODUCING COMPANY 15 mo
1997-06 — 2005-12 NORTH CENTRAL OIL CORP. 103 mo
1993-01 — 1997-05 CHEVRON U. S. A. INC. 53 mo

Wells (1)

WELL#APIOPERATORPERMITSDEPTHLAST_ISSUED
1642-039-32069DENBURY ONSHORE, LLC26,0002011-05-23