As filed with the Securities and Exchange Commission on December 6, 2016

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form S-3

REGISTRATION STATEMENT

UNDER THE SECURITIES ACT OF 1933

(Exact name of registrant as specified in its charter)

901 West Wall St., 3rd Floor

Midland, TX

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

William R. Broaddrick

Chief Financial Officer

6555 S. Lewis Ave, Suite 200

Tulsa, Oklahoma  74136

(918) 499-3880

(Name, address, including zip code, and telephone number, including are code, of agent for service)

With a copy to:

Mark L. Jones

Andrew Campbell

Baker & Hostetler LLP

811 Main Street, Suite 1100

Houston, TX 77002

Telephone: (713) 646-1395

Approximate Date of Commencement of Proposed Sale to the Public: From time to time after the effective date of this registration statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box: ¨ 

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box: x

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: x (Registration No. 333-200324)

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: ¨

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box: ¨

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box: ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

CALCULATION OF REGISTRATION FEE

This Registration Statement will become effective upon filing with the Securities and Exchange Commission in accordance with Rule 462(b) of the Securities Act.

EXPLANATORY NOTE AND INCORPORATION BY REFERENCE

This Registration Statement is being filed by the Company with respect to the registration of an additional maximum aggregate amount of the Company’s common stock, par value $0.001 per share, pursuant to Rule 462(b) under the Securities Act. This Registration Statement relates to the Prior Registration Statement, which was declared effective by the Securities and Exchange Commission on December 3, 2014. The Company is filing this Registration Statement for the sole purpose of increasing the maximum aggregate amount of common stock that may be offered by the Company by $3,593,125. Pursuant to Rule 462(b), the contents of the Prior Registration Statement are incorporated by reference into this Registration Statement.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Midland, State of Texas, on December 6, 2016.

Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed below by the following persons on behalf of the Registrant in the capacities and on the dates indicated below.

EXHIBIT INDEX