Filing Details

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G/A Under the Securities Exchange Act of 1934 Natural Gas Services Group, Inc ----------------------------------------------- (Name of Issuer) Common Stock ----------------------------------------------- (Title of Class of Securities) 63886Q109 ----------------------------------------------- (CUSIP Number) 12/31/2018 ----------------------------------------------- (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [ ] Rule 13d-1(b) [x] Rule 13d-1(c) [ ] Rule 13d-1(d) The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in 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).

- ------------------------------ CUSIP No. 63886Q109 - ------------------------------ 1. NAME OF REPORTING PERSON Oslo Asset Management AS, OAM - -------------------------------------------------------------------------- 2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP Not Applicable (a) [ ] (b) [ ] - --------------------------------------------------------------------------- 3. SEC USE ONLY - --------------------------------------------------------------------------- 4. CITIZENSHIP OR PLACE OF ORGANIZATION Norway - --------------------------------------------------------------------------- NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 5. SOLE VOTING POWER 970 958 - --------------------------------------------------------- 6. SHARED VOTING POWER None - ---------------------------------------------------------- 7. SOLE DISPOSITIVE POWER 970 958 - ------------------------------------------------- 8. SHARED DISPOSITIVE POWER None - --------------------------------------------------------------------------- 9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 970 958 - --------------------------------------------------------------------------- 10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES Not Applicable - --------------------------------------------------------------------------- 11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 7,40 - --------------------------------------------------------------------------- 12. TYPE OF REPORTING PERSON IA - --------------------------------------------------------------------------- CUSIP No. 63886Q109 - ------------------------------ Item 1(a) Name of Issuer: Natural Gas Services Inc Item 1(b) Address of Issuer's Principal Executive Offices: 508 West Wall Street, Suite 550 Midland TX 79701 Item 2(a) Name of Person(s) Filing: Oslo Asset Management AS Item 2(b) Address of Principal Business Office: Henrik Ibsens gate 20 0255 Oslo Norway Item 2(c) Citizenship: Norwegian public limited company Item 2(d) Title of Class of Securities: Common Stock Item 2(e) CUSIP Number: 63886Q109 Item 3 Type of Person: (e) OAM is an Investment Adviser in accordance with Rule 13d-1(b)(1)(ii)(F). Item 4 Ownership: (a) Amount beneficially owned: 970 958 (b) Percent of class: 7,40 (c) Number of shares as to which such person has: (i) Sole power to vote or to direct the vote: 970 958 (ii) Shared power to vote or to direct the vote: None (iii) Sole power to dispose or direct the disposition of: 970 958 (iv) Shared power to dispose or direct the disposition of: None Item 5 Ownership of Five Percent or Less of a Class: Not Applicable Item 6 Ownership of More than Five Percent on Behalf of Another Person: Not Applicable Item 7 Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company: CUSIP No. 63886Q109 - ------------------------------ Item 8 Identification and Classification of Members of the Group: Not Applicable Item 9 Notice of Dissolution of Group: Not Applicable Item 10 Certification: By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. 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. Date: 03/18/2018 Oslo Asset Management By: /s/ Annar Schiander --------------------------- Annar Schiander Chief Compliance Officer