Methods and apparatus for completing unconsolidated lateral well bores

Abstract

Improved methods and apparatus for completing unconsolidated subterranean zones penetrated by well bores are provided. The methods basically comprise the steps of placing a slotted pipe having openings formed therein which vary in size or in the number of openings along the length of the slotted pipe or both in the subterranean zone, isolating the annulus between the slotted pipe and the well bore and injecting particulate material into the annulus whereby the particulate material is uniformly packed therein.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to improved methods and apparatus for completing unconsolidated lateral well bores.[0003] 2. Description of the Prior Art[0004] Lateral well bores, i.e., well bores that are drilled horizontally or substantially in a horizontal direction from a vertical or substantially vertical primary well bore are often completed in unconsolidated formations containing loose and incompetent fines and sand which migrate with fluids produced from the formations. The presence of formation fines and sand in the produced fluids is undesirable in that the particles abrade tubular goods, producing equipment, pumps and the like and reduce the fluid production capabilities of the formations.[0005] In order to terminate or reduce the presence of formation fines and sand in produced fluids, completions utilizing gravel packs are often utilized. In a typical gravel pack completion, a screen is placed in the well bore and positioned within t...

AI Technical Summary

Benefits of technology

[0013] Another method of the present invention is comprised of the following steps. A slotted pipe is placed in the lateral well bore having openings formed therein through which the produced formation fluids flow and having an internal sand screen disposed therein. The slotted pipe includes openings that vary in size or vary in the number of openings along the length of the slotted pipe or both so that the produced formation fluids flow into the slotted pipe at substantially equal flow rates over the length of the slotted pipe. The annulus between the slotted pipe and the well bore and the annulus between the sand screen and the slotted pipe are isolated. Thereafter, particulate material is injected into the annulus between the slotted pipe and the well bore and the annulus between the slotted pipe and the sand screen whereby the particulate material is uniformly packed in the annuluses and the migration of formation fines and sand with produced fluids is prevented.

Problems solved by technology

The presence of formation fines and sand in the produced fluids is undesirable in that the particles abrade tubular goods, producing equipment, pumps and the like and reduce the fluid production capabilities of the formations.

Gravel bridges occur as the result of non-uniform gravel packing in the annulus due to the loss of carrier liquid from the gravel slurry into high permeability portions of the subterranean zone.

Another problem very often encountered in the completion of lateral well bores involves unequal production of formation fluids along the length of the lateral well bore.

However, the portion of a subterranean formation penetrated by the heel of a lateral well bore often experiences higher draw-down pressure than the portion of the well bore closest to the toe.

This in turn can cause the full production potential of the toe section to never be realized.

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