Occidental updates Western Midstream (NYSE: WES) 38.3% ownership stake

Rhea-AI Filing Summary

Occidental Petroleum and its affiliates have updated their ownership disclosure for Western Midstream Partners. They report beneficial ownership of 150,374,176 common units, representing 38.3% of Western Midstream’s outstanding common units as of October 31, 2025.

The filing explains that these units are held through several subsidiaries, primarily Western Gas Resources, Inc., APC Midstream Holdings, LLC and Anadarko USH1 Corporation. On February 3, 2026, Western Gas Resources, Inc. transferred and surrendered 15,307,402 common units to Western Midstream in connection with the closing of a previously disclosed Unit Redemption Agreement, and no other transactions in the units are reported since the prior amendment.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 9)

Western Midstream Partners, LP

(Name of Issuer)

Common Units Representing Limited Partner Interests

(Title of Class of Securities)

958669103

(CUSIP Number)

Nicole E. Clark
5 Greenway Plaza, Suite 110
Houston, TX, 77046
(713) 215-7000

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

02/03/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Occidental Petroleum Corporation

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 150,374,176.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 150,374,176.00

11

Aggregate amount beneficially owned by each reporting person

150,374,176.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

38.3 %

14

Type of Reporting Person (See Instructions)

HC, CO

Comment for Type of Reporting Person:

Represents (i) 140,912,118 common units representing limited partner interests in the Issuer ("Common Units") held by Western Gas Resources, Inc. ("WGRI"), (ii) 457,849 Common Units held by APC Midstream Holdings, LLC ("AMH") and (iii) 9,004,209 Common Units held by Anadarko USH1 Corporation ("AUSH1"). Occidental Petroleum Corporation ("Occidental") indirectly owns 100% of the issued and outstanding common stock of Anadarko Petroleum Corporation ("Anadarko"), which directly or indirectly owns 100% of the issued and outstanding equity interests of WGRI, AMH and AUSH1. Occidental may, therefore, be deemed to beneficially own the Common Units held by WGRI, AMH and AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

OXY USA Inc.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 150,374,176.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 150,374,176.00

11

Aggregate amount beneficially owned by each reporting person

150,374,176.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

38.3 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

Represents (i) 140,912,118 Common Units held by WGRI, (ii) 457,849 Common Units held by AMH and (iii) 9,004,209 Common Units held by AUSH1. OXY Oil Partners, Inc. indirectly owns 100% of the issued and outstanding common stock of Anadarko, which directly or indirectly owns 100% of the issued and outstanding equity interests of WGRI, AMH and AUSH1. Oxy Oil Partners, Inc. may be deemed to beneficially own the Common Units held by WGRI, AMH and AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

OXY Oil Partners, Inc.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 150,374,176.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 150,374,176.00

11

Aggregate amount beneficially owned by each reporting person

150,374,176.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

38.3 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

Represents (i) 140,912,118 Common Units held by WGRI, (ii) 457,849 Common Units held by AMH and (iii) 9,004,209 Common Units held by AUSH1. OXY Oil Partners, Inc. indirectly owns 100% of the issued and outstanding common stock of Anadarko, which directly or indirectly owns 100% of the issued and outstanding equity interests of WGRI, AMH and AUSH1. Oxy Oil Partners, Inc. may be deemed to beneficially own the Common Units held by WGRI, AMH and AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Baseball Merger Sub 2, Inc.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 150,374,176.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 150,374,176.00

11

Aggregate amount beneficially owned by each reporting person

150,374,176.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

38.3 %

14

Type of Reporting Person (See Instructions)

HC, OO

Comment for Type of Reporting Person:

Represents (i) 140,912,118 Common Units held by WGRI, (ii) 457,849 Common Units held by AMH and (iii) 9,004,209 Common Units held by AUSH1. Baseball Merger Sub 2, Inc. indirectly owns 100% of the issued and outstanding common stock of Anadarko, which directly or indirectly owns 100% of the issued and outstanding equity interests of WGRI, AMH and AUSH1. Baseball Merger Sub 2, Inc. may, therefore, be deemed to beneficially own the Common Units held by WGRI, AMH and AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Anadarko Petroleum Corporation

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 150,374,176.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 150,374,176.00

11

Aggregate amount beneficially owned by each reporting person

150,374,176.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

38.3 %

14

Type of Reporting Person (See Instructions)

HC, CO

Comment for Type of Reporting Person:

Represents (i) 140,912,118 Common Units held by WGRI, (ii) 457,849 Common Units held by AMH and (iii) 9,004,209 Common Units held by AUSH1. Anadarko directly or indirectly owns 100% of the issued and outstanding equity interests of WGRI, AMH and AUSH1 and may, therefore, be deemed to beneficially own the Common Units held by WGRI, AMH and AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Western Gas Resources, Inc.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 141,369,967.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 141,369,967.00

11

Aggregate amount beneficially owned by each reporting person

141,369,967.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

36.0 %

14

Type of Reporting Person (See Instructions)

HC, CO

Comment for Type of Reporting Person:

Represents (i) 140,912,118 Common Units held by WGRI and (ii) 457,849 Common Units held by AMH. In addition to its Common Units held of record, WGRI directly owns 100% of the issued and outstanding equity interests of AMH and may, therefore, be deemed to beneficially own the Common Units held by AMH. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

APC Midstream Holdings, LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 457,849.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 457,849.00

11

Aggregate amount beneficially owned by each reporting person

457,849.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.1 %

14

Type of Reporting Person (See Instructions)

OO, HC

Comment for Type of Reporting Person:

Represents 457,849 Common Units held by AMH. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Anadarko Holding Company

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UTAH

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 9,004,209.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 9,004,209.00

11

Aggregate amount beneficially owned by each reporting person

9,004,209.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.3 %

14

Type of Reporting Person (See Instructions)

HC, CO

Comment for Type of Reporting Person:

Represents 9,004,209 Common Units held by AUSH1. Anadarko Holding Company ("AHC") and Kerr-McGee Corporation ("KMG") together own 100% of the common stock of Kerr-McGee Worldwide Corporation ("KMWW"), and Anadarko and KMWW together indirectly own 100% of the common stock of AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Kerr-McGee Corporation

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 9,004,209.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 9,004,209.00

11

Aggregate amount beneficially owned by each reporting person

9,004,209.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.3 %

14

Type of Reporting Person (See Instructions)

HC, CO

Comment for Type of Reporting Person:

Represents 9,004,209 Common Units held by AUSH1. AHC and KMG together own 100% of the common stock of KMWW, and Anadarko and KMWW together indirectly own 100% of the common stock of AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Kerr-McGee Worldwide Corporation

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 9,004,209.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 9,004,209.00

11

Aggregate amount beneficially owned by each reporting person

9,004,209.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.3 %

14

Type of Reporting Person (See Instructions)

HC, CO

Comment for Type of Reporting Person:

Represents 9,004,209 Common Units held by AUSH1. KMWW and Anadarko together indirectly own 100% of the common stock of AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

CUSIP No. 958669103

1

Name of reporting person

Anadarko USH1 Corporation

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 9,004,209.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 9,004,209.00

11

Aggregate amount beneficially owned by each reporting person

9,004,209.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.3 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

Represents 9,004,209 Common Units held of record by AUSH1. The calculation is based on a total of 392,688,323 Common Units issued and outstanding as of October 31, 2025 after giving effect to the redemption reported herein.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Units Representing Limited Partner Interests
(b)	Name of Issuer: Western Midstream Partners, LP
(c)	Address of Issuer's Principal Executive Offices: 9950 Woodloch Forest Drive, Suite 2800, The Woodlands, TEXAS , 77380.
Item 1 Comment: This Amendment No. 9 amends and supplements the Schedule 13D filed with the Securities and Exchange Commission on August 19, 2019 (the "Original Schedule 13D," and as amended, the "Schedule 13D") relating to the common units representing limited partner interests (the "Common Units") in Western Midstream Partners, LP, a Delaware master limited partnership (the "Issuer") beneficially owned by Occidental Petroleum Corporation ("Occidental"), OXY USA Inc. ("OXY USA"), OXY Oil Partners, Inc. ("OOP"), Baseball Merger Sub 2, Inc. ("BMS"), Anadarko Petroleum Corporation ("Anadarko"), Western Gas Resources, Inc. ("WGRI"), APC Midstream Holdings, LLC ("AMH"), Anadarko Holding Company ("AHC"), Kerr-McGee Corporation ("KMG"), Kerr-McGee Worldwide Corporation ("KWC") and Anadarko USH1 Corporation ("AUSH1" and together with Occidental, OXY USA, OOP, BMS, Anadarko, WGRI, AMH, AHC, KMG and KWC, the "Reporting Persons"). Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Original Schedule 13D and subsequent amendments, as applicable. The filing of this Amendment No. 9 shall not be construed as an admission that any of the Reporting Persons is for the purposes of Section 13(d) or 13(g) of the Securities Exchange Act of 1934, the beneficial owner of any of the Common Units reported herein. Pursuant to Rule 13d-4, each of the Reporting Persons disclaims all such beneficial ownership in any such Common Units.
Item 5.	Interest in Securities of the Issuer
(a)	See the information on the cover pages of this Amendment No. 9 to the Schedule 13D, which is incorporated by reference herein.
(b)	See the information on the cover pages of this Amendment No. 9 to the Schedule 13D, which is incorporated by reference herein.
(c)	On February 3, 2026, WGRI transferred and surrendered 15,307,402 Common Units to the Issuer in connection with the closing of the transactions contemplated by the previously disclosed Unit Redemption Agreement. Except for the foregoing, none of the Reporting Persons, nor, to the Reporting Persons' knowledge, any of the Listed Persons, has effected any transactions in the Common Units since Amendment No. 8.
(d)	The Reporting Persons have the right to receive distributions from, and the proceeds from the sale of, the respective Common Units reported by such persons on the cover pages of the Schedule 13D and in this Item 5. Except for the foregoing, no other person is known by the Reporting Persons to have the right to receive or the power to direct the receipt of distributions from, or the proceeds from the sale of, Common Units beneficially owned by the Reporting Persons or, to the Reporting Persons' knowledge, the Listed Persons.
(e)	Not applicable.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Occidental Petroleum Corporation

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President, Corporate Secretary and Chief Compliance Officer
Date:	02/05/2026

OXY USA Inc.

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

OXY Oil Partners, Inc.

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

Baseball Merger Sub 2, Inc.

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

Anadarko Petroleum Corporation

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

Western Gas Resources, Inc.

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

APC Midstream Holdings, LLC

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

Anadarko Holding Company

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

Kerr-McGee Corporation

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

Kerr-McGee Worldwide Corporation

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

Anadarko USH1 Corporation

Signature:	/s/ Nicole E. Clark
Name/Title:	Nicole E. Clark, Vice President and Secretary
Date:	02/05/2026

FAQ

What does Occidental’s Schedule 13D/A Amendment No. 9 for Western Midstream (WES) disclose?

The amendment updates Occidental’s beneficial ownership in Western Midstream Partners to 150,374,176 common units, or 38.3% of outstanding units. It also notes an internal group transfer where Western Gas Resources, Inc. surrendered 15,307,402 units to the partnership under a previously disclosed Unit Redemption Agreement.

How many Western Midstream (WES) units does Occidental now beneficially own?

Occidental and its affiliated reporting entities beneficially own 150,374,176 Western Midstream common units. This stake represents 38.3% of the 392,688,323 common units outstanding as of October 31, 2025, after giving effect to the unit redemption described in the amendment.

What percentage of Western Midstream (WES) does Occidental’s group control after this amendment?

The reporting group led by Occidental Petroleum reports beneficial ownership of 38.3% of Western Midstream’s common units. This percentage is based on 392,688,323 units outstanding as of October 31, 2025, including adjustments for the redeemed units surrendered to the issuer.

Which entities within Occidental’s structure hold Western Midstream (WES) common units?

Units are held through several subsidiaries, mainly Western Gas Resources, Inc., APC Midstream Holdings, LLC and Anadarko USH1 Corporation. Parent entities such as Occidental, OXY Oil Partners, Anadarko and related Kerr-McGee entities are deemed beneficial owners through their 100% or joint ownership of these holding companies.

What transaction on February 3, 2026 is reported in the Western Midstream (WES) filing?

On February 3, 2026, Western Gas Resources, Inc. transferred and surrendered 15,307,402 Western Midstream common units to the partnership. This occurred in connection with closing the transactions under a previously disclosed Unit Redemption Agreement, and no other unit transactions have occurred since Amendment No. 8.

Do Occidental and affiliates claim full beneficial ownership of Western Midstream (WES) units?

The reporting entities list beneficial ownership based on their corporate structure, but each expressly disclaims being a beneficial owner for purposes of certain Exchange Act provisions. They rely on Rule 13d-4, stating the filing should not be construed as an admission of beneficial ownership of the reported common units.