Subsidiary

State or Other Jurisdiction of Formation

Pioneer Intermediate, Inc.

Delaware

Pioneer Investment, Inc.

Delaware

Pioneer NCS Energy Holdco, LLC

Texas

NCS Multistage, LLC

Texas

STS Logistics and Analytics, LLC

Oklahoma

STS Holdings, Inc.

Nevada

STS Tracer Services, Ltd.

Canada

NCS Multistage Norge

Norway

Repeat Precision, LLC

Texas

RJ Machine Mexico, S. de R.L. de C.V.

Mexico

NCS International, LLC

Texas

NCS Multistage Argentina S.R.L.

Argentina

NCS International 2, LLC

Texas

NCS Multistage Inc.

Canada