Washout Factors and Top of Cement

Pursuant to Statewide Rule 13(a)(C) and 13(A)(D), when using a calculation to determine the top of cement, the Railroad Commission of Texas (RRC) uses a baseline washout factor of 20 percent across most of the state, and 30 percent in coastal counties due to higher probabilities of encountering unconsolidated sands in the coastal region. A map showing these factors by county may be found below.

The RRC will also consider lesser washout factors submitted by operators on a case-by-case basis, provided the operator requesting the lesser washout factor submits supporting documentation (see Instruction D on Form W-15). An operator may request approval to apply a lesser washout factor across an area such as a field or county, but each operator’s drilling technology and practices, and supporting washout documentation will be evaluated independently of other operators’ data. Operators requesting a lesser washout factor should submit the request and supporting documentation to the appropriate RRC District Office.

Please click image to enlarge:
Texas Washout Map