Field Operating Experience in Locating and Recovering Landslide-Damaged Oil Wells
Authors: Johnson R.J. 
Published: December 2007

This paper was prepared for the 44th Annual California Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in San Francisco, Calif., April 4–5, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.

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Landslides have damaged 65 oil wells on Getty Oil Company's leases in the Ventura Avenue Field. During a landslide, some wells may remain connected to the surface while other wells may be buried. Well damage ranges from slight bending to complete severing of all casing strings, and depth of damage varies from 15' to 120'. Two major problems have been encountered when problems have been encountered when repair work is planned for a landslide damaged well. The first problem is to locate the undamaged well casing below the landslide. The second problem is to recover the well and replace the damaged casing.

Some methods used by Getty Oil Company to locate the undamaged portion of a well are conventional surveys, dip-needle surveys, magnetometer surveys, kinkmeter surveys, and test holes. In wells that remain connected to the surface following a landslide, an oriented kinkmeter survey may provide all of the information necessary for planning a well recovery program. For planning a well recovery program. For wells which are buried or have severed casing, conventional surveys, magnetic surveys, and test holes may provide enough information for planning recovery programs. Information on the movement, depth, and dimensions of a particular landslide may also be particular landslide may also be helpful or necessary.

Three methods have been used to recover landslide damaged wells in the Ventura Avenue Field. The simplest method is an open excavation made with standard earthmoving equipment. This method is limited to shallow depths and locations where the landslide would not be reactivated. To reach greater depths, special methods such as hand-dug or machine-dug shafts must be used. All three methods have been used successfully by Getty Oil Company.

Introduction

Landslides have affected oil production in the Ventura Avenue Field since production in the Ventura Avenue Field since 1926. On Getty Oil Company's leases, 143 wells are located on the 11 landslides shown in Figure 1. These slides vary in size from 1.5 to 150 acres, and cover 43 percent of the productive surface area. productive surface area.