KEYSTONE CATTLE CO.

Oil · District 08 · Lease #1422

Operator: PENNZOIL PETROLEUM COMPANY

Fields: FLYING -W-

Cum Oil

414k BBL

Cum Gas

3.0M MCF

casinghead

Wells

7

Production

1993-01 — 2026-04

Peak Month

1994-09

Production History

Cum Oil: 413,687 BBL Cum Gas: 3,026,344 MCF

RRC production reported through Apr 2026 · recent months incomplete

Decline Curve Analysis

qi

2,096 BBL/mo

Di (annual)

6.5%

b-factor

0.2

EUR

418,348 BBL

R-squared

0.670

type

hyperbolic

Operator History (from monthly production reports)

2023-03 — 2026-07 HIGHMARK ENERGY OPERATING, LLC 41 mo
2008-05 — 2023-02 LEGACY RESERVES OPERATING LP 178 mo
2000-04 — 2008-04 DEVON ENERGY PRODUCTION CO, L.P. 97 mo
1999-03 — 2000-03 PENNZENERGY EXP. & PROD., L.L.C. 13 mo
1995-02 — 1999-02 PENNZOIL EXPLORATION & PROD. CO. 49 mo
1993-01 — 1995-01 PENNZOIL PETROLEUM COMPANY 25 mo

Wells (7)

WELL#APIOPERATORPERMITSDEPTHLAST_ISSUED
213HIGHMARK ENERGY OPERATING, LLC311,7772017-06-12
192HIGHMARK ENERGY OPERATING, LLC210,5352017-04-10
377HIGHMARK ENERGY OPERATING, LLC39,9502009-01-16
376HIGHMARK ENERGY OPERATING, LLC211,9002008-11-26
146HIGHMARK ENERGY OPERATING, LLC29,8002003-07-22
372HIGHMARK ENERGY OPERATING, LLC110,1801985-03-14
315HIGHMARK ENERGY OPERATING, LLC111,7701980-11-10