Apache 9-21 Clarkson

API 4006320434 · Harding County, South Dakota · Buffalo field

ProducingOil

API

4006320434

Operator

Citation Oil and Gas Corp.

County

Harding

Field

Buffalo

Location

NESE Sec 21 Twp 021N Rng 03E

Permit

1364

Production

495 monthly filings with South Dakota, Mar 1985 to Jun 2026. Each product is in its own unit and the four are never added.

Cumulative oil

408,092 bbl

Cumulative gas

21,484 MCF

Cumulative water

88,948 bbl

Period	Oil (bbl)	Gas (MCF)	Water (bbl)	Days
Jun 2026	530	70	268	30
May 2026	559	72	296	31
Apr 2026	542	60	253	30
Mar 2026	524	72	281	31
Feb 2026	508	66	300	28
Jan 2026	524	72	278	31
Dec 2025	530	72	377	31
Nov 2025	539	70	270	30
Oct 2025	563	72	283	31
Sep 2025	557	70	278	30
Aug 2025	575	72	292	31
Jul 2025	626	72	305	31
Jun 2025	497	70	250	28
May 2025	583	72	283	31
Apr 2025	571	70	284	30
Mar 2025	612	72	297	31
Feb 2025	557	66	280	28
Jan 2025	536	72	261	31
Dec 2024	564	0	283	31
Nov 2024	562	70	282	30
Oct 2024	571	72	285	31
Sep 2024	566	70	284	30
Aug 2024	598	72	299	31
Jul 2024	573	72	293	31
Jun 2024	546	70	258	30
May 2024	585	72	288	31
Apr 2024	559	70	267	30
Mar 2024	581	72	279	31
Feb 2024	583	68	270	29
Jan 2024	463	56	220	23
Dec 2023	563	72	325	31
Nov 2023	549	70	268	30
Oct 2023	546	72	255	31
Sep 2023	545	70	245	30
Aug 2023	522	72	245	31
Jul 2023	556	72	265	31
Jun 2023	555	70	251	30
May 2023	539	72	247	31
Apr 2023	561	70	263	30
Mar 2023	596	72	268	31
Feb 2023	525	66	246	28
Jan 2023	603	62	261	31
Dec 2022	627	70	275	31
Nov 2022	529	70	251	30
Oct 2022	593	70	263	31
Sep 2022	566	70	250	30
Aug 2022	548	70	249	31
Jul 2022	586	70	270	31
Jun 2022	600	70	291	30
May 2022	403	70	328	21
Apr 2022	585	70	258	30
Mar 2022	583	70	242	31
Feb 2022	485	70	229	28
Jan 2022	582	70	242	31
Dec 2021	510	70	228	31
Nov 2021	517	70	223	30
Oct 2021	233	70	230	31
Sep 2021	811	70	209	30
Aug 2021	519	70	236	31
Jul 2021	531	70	259	31
Jun 2021	538	70	230	30
May 2021	597	70	242	31
Apr 2021	395	70	187	15
Mar 2021	363	70	163	24
Feb 2021	427	70	219	28
Jan 2021	503	70	217	31
Dec 2020	522	0	206	31
Nov 2020	513	70	215	30
Oct 2020	512	70	227	31
Sep 2020	509	70	202	29
Aug 2020	528	70	232	31
Jul 2020	519	70	285	31
Jun 2020	480	70	205	30
May 2020	525	70	231	31
Apr 2020	509	70	221	30
Mar 2020	558	70	201	31
Feb 2020	486	70	216	29
Jan 2020	535	70	215	31
Dec 2019	540	70	214	31
Nov 2019	453	70	266	30
Oct 2019	557	70	194	31
Sep 2019	550	70	209	30
Aug 2019	599	70	248	31
Jul 2019	626	70	274	31
Jun 2019	485	70	361	30
May 2019	541	70	217	31
Apr 2019	524	70	222	30
Mar 2019	549	70	224	31
Feb 2019	490	70	196	28
Jan 2019	537	70	257	31
Dec 2018	445	70	386	31
Nov 2018	507	70	196	30
Oct 2018	516	70	203	31
Sep 2018	504	70	197	30
Aug 2018	541	70	216	31
Jul 2018	539	70	396	31
Jun 2018	530	70	206	30
May 2018	556	70	220	31
Apr 2018	541	70	204	30
Mar 2018	553	70	220	31
Feb 2018	508	70	200	28
Jan 2018	567	70	—	31
Nov 2017	538	70	3,201	30
Oct 2017	563	70	225	31
Sep 2017	540	70	213	30
Aug 2017	564	70	219	31
Jul 2017	565	70	218	31
Jun 2017	545	70	215	30
May 2017	571	70	222	31
Apr 2017	556	70	222	30
Mar 2017	572	72	213	31
Feb 2017	517	70	200	28
Jan 2017	583	70	230	31
Dec 2016	575	70	217	31
Nov 2016	556	70	214	30
Oct 2016	576	70	226	31
Sep 2016	572	70	211	30
Aug 2016	585	70	218	31
Jul 2016	573	72	223	31
Jun 2016	588	60	207	30
May 2016	594	62	221	31
Apr 2016	579	60	208	30
Mar 2016	592	62	214	31
Feb 2016	569	60	203	29
Jan 2016	591	62	222	31
Dec 2015	609	62	217	31
Nov 2015	578	60	218	30
Oct 2015	611	62	214	31
Sep 2015	597	60	212	30
Aug 2015	614	62	221	31
Jul 2015	616	62	218	31
Jun 2015	608	60	29	30
May 2015	630	62	222	31
Apr 2015	610	60	210	30
Mar 2015	643	62	221	31
Feb 2015	570	56	205	28
Jan 2015	649	62	219	31
Dec 2014	663	62	229	31
Nov 2014	663	60	230	30
Oct 2014	590	50	290	25
Sep 2014	599	58	203	29
Aug 2014	644	62	216	31
Jul 2014	659	62	216	31
Jun 2014	636	60	210	30
May 2014	663	62	218	31
Apr 2014	659	60	212	30
Mar 2014	681	62	219	31
Feb 2014	687	56	213	28
Jan 2014	530	48	197	24
Dec 2013	633	62	215	31
Nov 2013	650	60	207	30
Oct 2013	681	62	213	31
Sep 2013	660	60	214	30
Aug 2013	676	62	215	31
Jul 2013	683	62	212	31
Jun 2013	668	60	217	30
May 2013	691	62	221	31
Apr 2013	672	60	217	30
Mar 2013	692	62	216	31
Feb 2013	622	56	196	28
Jan 2013	692	62	218	31
Dec 2012	698	62	209	31
Nov 2012	664	60	221	30
Oct 2012	706	62	216	31
Sep 2012	685	60	211	30
Aug 2012	714	62	220	31
Jul 2012	709	62	215	31
Jun 2012	696	60	210	30
May 2012	712	62	215	31
Apr 2012	697	60	211	30
Mar 2012	728	62	217	31
Feb 2012	676	58	203	29
Jan 2012	732	62	215	31
Dec 2011	728	62	214	31
Nov 2011	701	60	201	30
Oct 2011	725	62	209	31
Sep 2011	715	60	211	30
Aug 2011	712	62	208	31
Jul 2011	746	62	214	31
Jun 2011	698	60	197	30
May 2011	733	62	211	31
Apr 2011	718	60	200	30
Mar 2011	736	62	208	31
Feb 2011	666	56	179	28
Jan 2011	741	62	198	31
Dec 2010	730	62	192	31
Nov 2010	714	60	190	30
Oct 2010	741	62	215	31
Sep 2010	712	60	186	29
Aug 2010	738	62	191	31
Jul 2010	755	62	193	31
Jun 2010	724	60	185	30
May 2010	762	62	185	31
Apr 2010	742	60	181	30
Mar 2010	790	62	192	31
Feb 2010	764	56	172	28
Jan 2010	713	52	149	26
Dec 2009	681	56	158	28
Nov 2009	732	60	174	30
Oct 2009	762	62	181	31
Sep 2009	734	60	174	30
Aug 2009	770	62	178	31
Jul 2009	765	62	173	31
Jun 2009	732	60	183	30
May 2009	783	62	177	31
Apr 2009	762	60	170	30
Mar 2009	770	62	172	31
Feb 2009	696	56	153	28
Jan 2009	788	62	180	31
Dec 2008	796	62	178	31
Nov 2008	729	54	154	27
Oct 2008	786	62	173	31
Sep 2008	769	60	172	30
Aug 2008	791	62	171	31
Jul 2008	805	62	191	31
Jun 2008	828	60	177	30
May 2008	574	0	110	18
Apr 2008	756	60	161	30
Mar 2008	783	62	163	31
Feb 2008	732	58	152	29
Jan 2008	782	62	152	31
Dec 2007	785	62	165	31
Nov 2007	750	60	158	30
Oct 2007	793	62	163	31
Sep 2007	762	60	155	30
Aug 2007	788	62	161	31
Jul 2007	781	62	162	31
Jun 2007	745	90	173	30
May 2007	795	62	151	31
Apr 2007	770	60	154	30
Mar 2007	788	62	162	31
Feb 2007	717	56	144	28
Jan 2007	790	62	160	31
Dec 2006	786	62	158	31
Nov 2006	773	60	153	30
Oct 2006	781	62	165	31
Sep 2006	767	60	151	30
Aug 2006	793	62	157	31
Jul 2006	796	62	154	31
Jun 2006	786	60	151	30
May 2006	836	62	166	31
Apr 2006	700	52	130	26
Mar 2006	805	62	151	31
Feb 2006	729	56	137	28
Jan 2006	807	60	153	31
Dec 2005	792	62	147	31
Nov 2005	783	60	146	30
Oct 2005	810	62	148	31
Sep 2005	766	60	165	30
Aug 2005	804	62	161	31
Jul 2005	822	62	151	31
Jun 2005	789	60	144	30
May 2005	824	62	149	31
Apr 2005	790	60	154	30
Mar 2005	783	62	140	31
Feb 2005	717	56	127	28
Jan 2005	804	62	147	31
Dec 2004	803	62	150	31
Nov 2004	776	60	158	30
Oct 2004	812	62	147	31
Sep 2004	785	60	136	30
Aug 2004	816	62	144	31
Jul 2004	812	62	145	31
Jun 2004	786	60	138	30
May 2004	816	62	145	31
Apr 2004	788	60	137	30
Mar 2004	821	62	138	31
Feb 2004	779	58	133	29
Jan 2004	799	62	136	31
Dec 2003	820	62	139	31
Nov 2003	790	60	130	30
Oct 2003	821	62	145	31
Sep 2003	800	60	132	30
Aug 2003	829	62	140	31
Jul 2003	830	62	141	31
Jun 2003	803	60	138	30
May 2003	841	62	143	31
Apr 2003	850	60	142	30
Mar 2003	736	52	113	26
Feb 2003	725	56	117	28
Jan 2003	814	62	137	31
Dec 2002	819	62	137	31
Nov 2002	790	60	133	30
Oct 2002	816	62	141	31
Sep 2002	798	60	143	30
Aug 2002	825	62	144	31
Jul 2002	824	62	140	31
Jun 2002	792	60	141	30
May 2002	827	62	150	31
Apr 2002	807	60	144	30
Mar 2002	830	62	141	31
Feb 2002	754	56	141	28
Jan 2002	773	62	116	31
Dec 2001	819	62	134	31
Nov 2001	804	60	121	30
Oct 2001	827	62	132	31
Sep 2001	792	60	133	30
Aug 2001	814	62	146	31
Jul 2001	832	62	128	31
Jun 2001	809	60	125	30
May 2001	832	62	126	31
Apr 2001	830	60	124	30
Mar 2001	858	62	133	31
Feb 2001	741	56	114	28
Jan 2001	819	62	127	31
Dec 2000	811	62	126	31
Nov 2000	791	60	121	30
Oct 2000	819	62	129	31
Sep 2000	790	60	3,683	30
Aug 2000	818	62	122	31
Jul 2000	792	62	136	31
Jun 2000	793	60	117	30
May 2000	813	62	121	31
Apr 2000	786	60	117	30
Mar 2000	817	62	120	31
Feb 2000	767	58	112	29
Jan 2000	807	62	118	31
Dec 1999	814	62	119	31
Nov 1999	785	60	111	30
Oct 1999	818	62	110	31
Sep 1999	789	60	110	30
Aug 1999	821	62	109	31
Jul 1999	814	62	115	31
Jun 1999	792	60	106	30
May 1999	817	62	116	31
Apr 1999	789	60	112	30
Mar 1999	827	62	108	31
Feb 1999	743	56	104	28
Jan 1999	851	62	125	31
Dec 1998	822	62	122	31
Nov 1998	767	60	95	30
Oct 1998	821	62	111	31
Sep 1998	801	60	110	30
Aug 1998	822	62	111	31
Jul 1998	821	62	115	31
Jun 1998	810	60	114	30
May 1998	835	62	112	31
Apr 1998	801	60	103	30
Mar 1998	833	62	101	31
Feb 1998	767	0	107	28
Jan 1998	835	0	117	31
Dec 1997	848	0	110	31
Nov 1997	803	0	115	30
Oct 1997	850	0	111	31
Sep 1997	826	0	107	30
Aug 1997	861	0	118	31
Jul 1997	867	0	121	31
Jun 1997	829	0	101	30
May 1997	878	0	109	31
Apr 1997	839	0	108	30
Mar 1997	887	0	113	31
Feb 1997	799	0	105	28
Jan 1997	896	0	117	31
Dec 1996	887	0	113	31
Nov 1996	854	0	104	29
Oct 1996	893	0	126	31
Sep 1996	876	0	112	30
Aug 1996	935	0	109	31
Jul 1996	898	0	121	31
Jun 1996	901	0	107	30
May 1996	942	0	108	31
Apr 1996	929	0	110	30
Mar 1996	975	0	105	31
Feb 1996	907	0	92	28
Jan 1996	969	0	120	31
Dec 1995	991	0	120	31
Nov 1995	981	0	110	30
Oct 1995	1,020	0	116	31
Sep 1995	1,019	0	118	30
Aug 1995	1,071	0	398	31
Jul 1995	1,108	0	137	31
Jun 1995	1,091	0	129	30
May 1995	1,180	0	130	31
Apr 1995	1,177	0	138	30
Mar 1995	1,257	0	142	31
Feb 1995	1,163	0	145	28
Jan 1995	1,350	0	150	31
Dec 1994	1,359	0	151	31
Nov 1994	1,334	0	151	30
Oct 1994	1,388	0	156	31
Sep 1994	1,352	0	155	30
Aug 1994	1,425	0	170	31
Jul 1994	1,501	0	182	31
Jun 1994	1,198	0	119	24
May 1994	1,462	0	160	31
Apr 1994	1,407	0	156	30
Mar 1994	1,484	0	163	31
Feb 1994	1,380	0	154	28
Jan 1994	1,535	0	164	31
Dec 1993	1,550	0	179	31
Nov 1993	1,550	0	172	30
Oct 1993	1,654	0	186	31
Sep 1993	1,658	0	205	30
Aug 1993	1,837	0	216	31
Jul 1993	2,072	0	274	31
Jun 1993	1,942	0	399	28
May 1993	1,175	0	326	26
Apr 1993	943	0	113	30
Mar 1993	984	0	113	31
Feb 1993	868	0	99	28
Jan 1993	1,005	0	128	31
Dec 1992	956	0	92	31
Nov 1992	913	0	133	30
Oct 1992	983	0	92	31
Sep 1992	945	0	98	30
Aug 1992	967	0	110	31
Jul 1992	978	0	97	30
Jun 1992	955	0	89	30
May 1992	957	0	118	31
Apr 1992	954	0	94	30
Mar 1992	972	0	98	31
Feb 1992	908	0	101	29
Jan 1992	970	0	109	31
Dec 1991	974	0	104	31
Nov 1991	941	0	101	30
Oct 1991	961	0	101	31
Sep 1991	935	0	103	30
Aug 1991	963	0	104	31
Jul 1991	965	0	104	31
Jun 1991	939	0	96	30
May 1991	952	0	114	31
Apr 1991	933	0	93	30
Mar 1991	969	0	98	31
Feb 1991	877	0	84	28
Jan 1991	949	0	98	31
Dec 1990	951	0	103	31
Nov 1990	934	0	87	30
Oct 1990	964	0	104	31
Sep 1990	935	0	104	30
Aug 1990	987	0	111	31
Jul 1990	1,079	0	110	30
Jun 1990	614	0	122	16
May 1990	943	0	137	31
Apr 1990	904	0	108	30
Mar 1990	942	0	95	31
Feb 1990	850	0	84	28
Jan 1990	946	0	40	31
Dec 1989	940	0	95	31
Nov 1989	916	0	94	30
Oct 1989	949	0	94	31
Sep 1989	902	0	91	30
Aug 1989	952	0	94	31
Jul 1989	939	0	92	31
Jun 1989	920	0	89	30
May 1989	949	0	91	31
Apr 1989	922	0	86	30
Mar 1989	961	0	93	31
Feb 1989	864	0	84	28
Jan 1989	956	0	93	31
Dec 1988	964	0	92	30
Nov 1988	937	0	95	30
Oct 1988	976	0	99	31
Sep 1988	950	0	82	30
Aug 1988	963	0	93	31
Jul 1988	996	0	64	31
Jun 1988	976	0	70	30
May 1988	1,034	0	79	29
Apr 1988	999	0	83	30
Mar 1988	1,044	0	73	31
Feb 1988	990	0	77	29
Jan 1988	1,082	0	56	31
Dec 1987	1,103	0	90	31
Nov 1987	1,110	0	94	30
Oct 1987	1,211	0	85	26
Sep 1987	665	0	47	19
Aug 1987	1,157	0	78	31
Jul 1987	1,154	0	102	30
Jun 1987	1,183	0	80	30
May 1987	1,198	0	74	31
Apr 1987	1,083	0	64	26
Mar 1987	1,232	0	46	31
Feb 1987	1,142	0	71	28
Jan 1987	1,284	0	75	31
Dec 1986	1,314	0	80	31
Nov 1986	1,317	0	63	30
Oct 1986	1,310	0	63	26
Sep 1986	1,334	0	75	30
Aug 1986	1,437	0	61	30
Jul 1986	1,485	0	34	29
Jun 1986	1,446	0	87	29
May 1986	1,534	0	61	31
Apr 1986	1,489	0	135	30
Mar 1986	1,602	0	96	28
Feb 1986	1,487	0	80	28
Jan 1986	1,708	0	21	31
Dec 1985	2,095	0	37	31
Nov 1985	1,749	0	26	30
Oct 1985	1,920	0	32	31
Sep 1985	1,972	0	28	30
Aug 1985	2,167	0	30	30
Jul 1985	2,379	0	30	30
Jun 1985	1,929	0	117	28
May 1985	2,023	0	164	31
Apr 1985	2,247	0	23	29
Mar 1985	2,221	0	73	18

A dash is a period the well filed with no volume for that product.

Formation tops

South Dakota records 18 formations for this well, shallowest first.

Formation	Top (ft)	Age
Greenhorn Limestone	3,320	Cretaceous
Dakota Mud	4,314	Cretaceous
Piper Formation	5,251	Triassic
Spearfish Formation	5,424	Triassic/Permian
Pine Salt, Spearfish Formation	5,576	Permian
Minnekahta Limestone	5,865	Permian
Opeche Shale	5,906	Permian
Charles Formation	6,528	Mississippian
Mission Canyon Limestone	6,961	Mississippian
Lodgepole Limestone	7,330	Mississippian
Duperow Formation	7,798	Devonian
Interlake Dolomite	7,954	Silurian
Stonewall Limestone	8,160	Silurian/Ordovician
Stony Mountain Formation	8,237	Ordovician
Red River Formation	8,310	Ordovician
Unit A, Red River Formation	8,320	Ordovician
Unit B, Red River Formation	8,348	Ordovician
Unit C, Red River Formation	8,403	Ordovician

A dash is a formation South Dakota records for this well without a depth.

Completion

South Dakota files 1 completion report for this well.

Vertical Well

ProducingOil

Spudded

1985-01-29

Completed

1985-03-13

Measured depth

8,450 ft

True vertical depth

8,450 ft

Intervals

Formation	Perforated (ft)
Unit A, Red River Formation	8,311–8,318
Unit A, Red River Formation	8,321–8,326
Unit B, Red River Formation	8,348–8,364

Location

45.767746, -103.751207

45.76775, -103.75121 · Surface location as filed with South Dakota⌘ or Ctrl + scroll to zoom

Every well in Harding County, South Dakota

South Dakota state record, from SD_wells_SDOILexport_Export__wells_Table_4_Web.parquet. Corpus built 2026-09-11.