X0306 4 2018-08-21 0001362705 Sanchez Midstream Partners LP SNMP 0001656530 Stonepeak Catarina Holdings LLC 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001656529 Stonepeak Catarina Upper Holdings LLC 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001656528 Stonepeak Infrastructure Fund (Orion AIV) LP 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001656527 Stonepeak Associates LLC 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001656526 Stonepeak GP Holdings LP 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001656525 Stonepeak GP Investors LLC 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001656524 Stonepeak GP Investors Manager LLC 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001550758 Dorrell Michael B. 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks 0001550764 Vichie Trent D 717 FIFTH AVENUE, 25TH FLOOR NEW YORK NY 10022 true true See Remarks Class B Preferred Units 2018-08-21 4 A 0 310009 A Common Units 310009 31310896 D These Class B Preferred Units (the "Preferred Units") were payable by the Issuer on August 31, 2018, to Preferred Unit holders of record on August 21, 2018, in satisfaction of the non-cash component of the second quarter 2018 distribution on the Preferred Units. The Preferred Units are convertible into Common Units at any time, at the holder's election, subject to the requirement to convert a minimum of $17.5 million of Preferred Units. The Preferred Units have no expiration date. Each Preferred Unit is currently convertible into one Common Unit. These Preferred Units are owned directly by Stonepeak Catarina Holdings LLC, and indirectly by Stonepeak Catarina Upper Holdings LLC, Stonepeak Infrastructure Fund (Orion AIV) LP, Stonepeak Associates LLC, Stonepeak GP Holdings LP, Stonepeak GP Investors LLC, Stonepeak GP Investors Manager LLC, Michael Dorrell and Trent Vichie. Stonepeak Catarina Upper Holdings LLC is the managing member of Stonepeak Catarina Holdings LLC. Stonepeak Infrastructure Fund (Orion AIV) LP is the managing member of Stonepeak Catarina Upper Holdings LLC. Stonepeak Associates LLC is the general partner of Stonepeak Infrastructure Fund (Orion AIV) LP. Stonepeak GP Holdings LP is the sole member of Stonepeak Associates LLC. Stonepeak GP Investors LLC is the general partner of Stonepeak GP Holdings LP. Stonepeak GP Investors Manager LLC is the managing member of Stonepeak GP Investors LLC. Each of Michael Dorrell and Trent Vichie serve as a managing member of Stonepeak GP Investors Manager LLC. Each Reporting Person disclaims beneficial ownership of the Preferred Units except to the extent of his or its pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the Preferred Units for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or for any other purpose. Exhibit 99.1: Additional Signatures. Solely for purposes of Section 16 of the Exchange Act, each of the Reporting Persons may be deemed to be directors-by-deputization by virtue of Stonepeak Catarina Holdings LLC's contractual right to, based on its current ownership, designate two persons to serve on the board of directors of the General Partner of the Issuer (the "Board"). Jack Howell and Luke Taylor, each an employee of Stonepeak Catarina Holdings LLC, are members of the Board. /s/ Michael Dorrell 2019-02-04 /s/ Trent Vichie 2019-02-04