LEASE AMENDMENT #12 DIAMONDBACK E & P LLC

LEASED PREMISES. As of the 14^th Floor Commencement Date (as defined below) and subject to the terms and condition of this Lease Amendment # 12, Section 1.5 "Leased Premises" of the Lease Agreement shall be amended to add approximately 7,030 square feet of Net Rentable Area located on the fourteenth (14^th) floor of One Fasken Center as more fully diagrammed on the floor plans attached hereto and made a part hereof as Exhibit "B-3" ("14^th Floor Expansion Space"). Said 14^th Floor Expansion Space is comprised of approximately 469 square feet of Net Rentable Area ("Suite 1435"), approximately 1,543 square feet of Net Rentable Area ("Suite 1450"), approximately 2,277 square feet of Net Rentable Area ("Suite 1460"), and approximately 2,741 square feet of Net Rentable Area ("Suite 1485"). The term "Leased Premises" shall hereinafter mean and include the 14^th Floor Expansion Space. The Leased Premises, with the 14^th Floor Expansion Space, will then consist of a total of approximately 21,421 square feet of Net Rentable Area, which represents 5.08% of the total Net Rentable Area of the Building, such total Net Rentable Area of the Building being 421,546 square feet. Lessor and Lessee acknowledge and agree that the aforesaid description of the size and square footage of the Leased Premises and the Building are an approximation, which the parties agree is reasonable and payments made thereupon are not subject to dispute.    

SUBJECT TO VACATING. Lessor's obligation to tender possession of the 14^th Floor Expansion Space hereunder is subject to the current tenant, Arabella Petroleum Company, LLC, vacating the entire 14^th Floor Expansion Space on or before October 31, 2014; provided, however, that if the current tenant, Arabella Petroleum Company, LLC, does not vacate all of the 14^th Floor Expansion Space within six (6) months from the Effective Date, Lessee or Lessor shall have the right to terminate this Lease Amendment #12 by delivery of written notice to the other within thirty (30) days after the aforesaid six (6) month period but prior to the date of actual delivery of the 14^th Floor Expansion Space to Lessee.

LEASE TERM. The Lease Term for the 14th Floor Expansion Space shall be for a period commencing on the later of (a) the date that the entire 14^th Floor Expansion Space is vacant and delivered to Lessee, or (b) November 1, 2014 (the "14^th Floor Commencement Date"), and expiring on May 31, 2016.

BASE YEAR. The Base Year for Operating Expenses and Tax Expenses for the 14^th Floor Expansion Space shall be the calendar year 2014.

PARKING. Effective as of the 14^th Floor Commencement Date, Lessor agrees to provide sixteen (16) additional parking spaces with respect to the 14^th Floor Expansion Space during the Term, in the designated areas, at the following rate per space per month plus applicable sales tax: