Exhibit 99.1
JOINT FILING AGREEMENT
Pursuant to Rule13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned agree that the Statement on Schedule 13G to which this exhibit is attached is filed on behalf of each of them.
| Dated: February 26, 2018 | ||||||
| HCperf Holdings B.V. | ||||||
| By: | /s/ J. Will Franklin | |||||
| Name: | J. Will Franklin | |||||
| Title: | Authorized Person | |||||
| LRP IV Luxembourg Holdings S.a.r.l. | ||||||
| By: | /s/ J. Will Franklin | |||||
| Name: | J. Will Franklin | |||||
| Title: | Authorized Person | |||||
| Lime Rock Partners IV, L.P. | ||||||
| By: | /s/ J. Will Franklin | |||||
| Name: | J. Will Franklin | |||||
| Title: | Authorized Person | |||||
| LRP V Luxembourg Holdings S.a.r.l. | ||||||
| By: | /s/ J. Will Franklin | |||||
| Name: | J. Will Franklin | |||||
| Title: | Authorized Person | |||||
| Lime Rock Partners V, L.P. | ||||||
| By: | /s/ J. Will Franklin | |||||
| Name: | J. Will Franklin | |||||
| Title: | Authorized Person | |||||
* | ||||||
| Jonathan C. Farber | ||||||
* | ||||||
| John T. Reynolds | ||||||
| * By: /s/ Kris Agarwal | ||||||
| Kris Agarwal,Attorney-in-Fact | ||||||
