January 11, 2018 Seneca Resources Corporation Houston, Texas 77002 Attn: Ben Elmore

Exhibit 2.3

  

January 11, 2018

Seneca Resources Corporation

0000 Xxxxxxxxx Xxxxxx, Xxxxx 0000

Xxxxxxx, Xxxxx 00000

Attn: Xxx Xxxxxx

Re: Purchase and Sale Agreement dated as of October 20, 2017 between SENECA RESOURCES CORPORATION, a Pennsylvania corporation (“Seller”); and CARBON CALIFORNIA COMPANY, LLC, a Delaware limited liability company (“Purchaser”), as amended by that certain amendment dated December 15, 2017 (collectively, the “Purchase and Sale Agreement”)

Gentlemen:

When executed by you below, this letter shall confirm the agreement between Seller and Purchaser to amend the Purchase and Sale Agreement in the following respect:

(1)     A new Section 9.05 is added to the Purchase and Sale Agreement which shall read as follows:

“Section 9.05 Pipeline Franchise. The City of Fillmore shall have either (i) granted a ten (10) year extension of the Franchise for Oil, Gas, and Other Hydrocarbon Substances or Water Pipelines (Ordinance No. 08-804) or (ii) granted a new Franchise for Oil, Gas, and Other Hydrocarbon Substances or Water Pipelines, in either event, readily assignable to Purchaser and on terms and conditions reasonably acceptable to Purchaser.”

(2)     Section 10.01 is amended by changing the Closing Date from “January 10, 2018” to “January 31, 2018.”

(3)     Section 13.01(d), is amended by replacing the date “January 10, 2018” with the date “January 31, 2018.”

Otherwise the Purchase and Sale Agreement shall remain in full force and effect, in accordance with its existing terms and provisions.

This Amendment may be executed in any number of counterparts, and each counterpart hereof shall be effective as to each Party that executes the same whether or not all Parties execute the same counterpart, provided that each Party executes at least one counterpart. If counterparts of this Amendment are executed, the signature pages from various counterparts may be combined into one composite instrument for all purposes. All counterparts together shall constitute only one agreement, but each counterpart shall be considered an original. This Amendment may be executed and delivered by exchange of facsimile or PDF copies showing the signatures of the Parties, and those facsimile or PDF copies showing the signatures of the Parties will constitute originally signed copies of the same agreement requiring no further execution.

[Signatures Page Follows]

0000 Xxxxxxxx, Xxxxx 0000, Xxxxxx, Xxxxxxxx 00000	Telephone 000 000 0000  Facsimile 000 000 0000
0000 Xxxxxxx Xxxxx, Xxxxx 000, Xxxxxxxxx, Xxxxxxxx 00000	Telephone 000 000 0000  Facsimile 000 000 0000
00000 X. Xxxxxxxxx Xx, Xxxxx X-00, Xxxxx Xxxxx, Xxxxxxxxxx 00000	Telephone 000 000 0000  Facsimile 000 000 0000

AGREED AND ACCEPTED:
CARBON CALIFORNIA COMPANY, LLC
By:	Carbon Natural Gas Company, Its Manager
By:	/s/ Xxxxxxx X. XxXxxxxx
	Xxxxxxx X. XxXxxxxx,
	Chief Executive Officer
SENECA RESOURCES CORPORATION
By:	/s/ Xxxx X. XxXxxxxx
	Xxxx X. XxXxxxxx
	President

Signature Page