Limiting Drilling Parameters to Control Mud Losses in the Dammam Formation, South Rumaila Field, Iraq


Lost circulation is a challenging problem particularly in the Dammam formation of the South Rumaila Field, Iraq. Drilling engineers are challenged to select the optimum value for key drilling parameters such as ECD, Yp, MW, WOB, ROP and RPM to mitigate mud losses in this zone. Many of these drilling parameters are inter-related and the overall impact of changing key parameters requires extensive drilling experience or study. A multi-regression analysis was performed on mud loss event data for more than 75 wells drilled in the Dammam formation. From this analysis, a model was developed to predict total mud losses. Mud loss was found to be significantly affected by MW, ECD and ROP. Models for these key parameters were also developed from multiregression analysis. The models were confirmed with additional well data from new wells drilled in the field. The models developed in this work provides a method for setting predicted mud losses, then limiting the operational drilling parameters to mitigate such losses in the future wells in fields with similar lithology.

Meeting Name

51st US Rock Mechanics / Geomechanics Symposium 2017 (2017: Jun. 25-28, San Francisco, CA)


Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Infill drilling; Lithology; Regression analysis; Respirators; Rock mechanics, Drilling parameters; In-field; Lost circulation; Mud loss; Multi-regression analysis; Optimum value; Well data, Well drilling

Geographic Coverage


International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


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© 2017 American Rock Mechanics Association (ARMA), All rights reserved.

Publication Date

01 Jun 2017

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