Frictional Forces in Oils Well Casing Strings by Using FEA

This presentation was made at CAASE18, The Conference on Advancing Analysis & Simulation in Engineering. CAASE18 brought together the leading visionaries, developers, and practitioners of CAE-related technologies in an open forum, to share experiences, discuss relevant trends, discover common themes, and explore future issues.

Resource Abstract

During the normal bore drilling process in deep onshore and offshore oil and gas wells no straight runs are achieved and drag forces is one of the main problems when running casing thorough the different casing strings down the hole. Once the conductor casing at the wellhead is placed and the surface casing is installed the subsequent well boring continues and smaller diameter casing strings will be run/installed as different depths until the final depth of the well is achieved.
Inner casing strings have to run inside an annular casing which might not be totally straight, in which case the inner casing could find frictional forces due to contacts on the bends down the hole.
This analysis can predict what those potential frictional forces would be; based on the normal forces that an inner casing string would have throughout the non-straight path of the outer casing.
In this paper a simple method using FEA, by using Abaqus software, is developed in order to predict the level of those normal forces due to the contact of the installed casing down the hole. This method performs the calculation of normal forces exerted by a piping string; as it was deformed into a similar shape to that of the outer casing. For simulating the deformation of the outer casing pipe ring sections are used at the bends and turns (change in angle) of the actual outer casing and then are displaced to duplicate the outer casing overall shape down the hole. Verification of the numerical analysis results are carried out by field testing’s at the ESI facility. An artifact was fabricated to produce bends and turns on an outer/inner pipe string assembly and then to measure the frictional force required to slide the inner pipe for different deformations of the casing. The results of this paper corroborated that the method developed with ABAQUS FEA procedures would yield precise calculations of the casing frictional forces for both onshore and offshore oil wells.

Document Details

AuthorGodoy. F
Date 5th June 2018
OrganisationEngineering Systems Inc. (ESI)


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