How to Select the Correct Sand Control System for Your Well

Abstract

Abstract There has long been a need for a guide to the selection of the sand control system needed for a particular well. There are four types of systems in use today:screens, gravel packing,sand consolidation anda resin-coated particulate such as sand. Although universal agreement may not be possible at this time, there are certain guidelines that are followed. The factors involved include formation permeability, clay and silt content of formation, interval length, number of zones, homogeneity, well history, type completion, depth, expense of rig time and others. This paper will consider these factors and their influence on the selection of sand control systems. Introduction The problem of controlling sand production in oil and gas wells has increased significantly in importance in the past few decades as new offshore oil provinces have been discovered and developed. The oil produced in many fields, particularly in south Louisiana, offshore Louisiana and California could not be economically produced if effective means of sand control were not available. Many papers have been published over the years describing the various sand control systems available to the industry. Much has also been written concerning the proper techniques for applying the various systems. There is no doubt that much progress has been made in solving the problem of sand control. There remains, however, a great degree of controversy and much divergence of opinion as to which method of sand control should be applied in any particular situation. Admittedly, this is a controversial problem, but the authors feel that certain guidelines can be established on the basis of experience with the various systems in use. The purpose of this paper is to review the four main methods of sand control that are in widespread use and to discuss those factors which are most important in the selection of the method best suited for a particular well. METHODS The four most widely used methods are (1) screens, (2) gravel packs, (3) sand consolidation using resin and (4) gravel packs with packs, (3) sand consolidation using resin and (4) gravel packs with resin-coated particles. Before setting the guidelines as to which method of sand control will do the best job for the money under a specific set of conditions, these four methods need to be defined. There are so many variations of each that our definition will have to be broad and include what we take to be typical or normal under most conditions. Regardless of the method used, each treatment must be properly designed and applied if effective sand control without excessive loss of productivity is to be obtained. SCREENS There are many types of screens, such as slotted liners and wire-wrapped liners, available for use as mechanical barriers. In many cases screens perform satisfactorily for preventing sand production. In more cases, however, they are not sufficient. When production. In more cases, however, they are not sufficient. When they work they are the cheapest method available. Their primary shortcoming lies in the fact that some sand must move to the screen before the real sand barrier of formation sand can be formed. Such a sand barrier cannot match the flow capacity of the well since, in effect, it reduces the wellbore diameter. Moreover, once the formation sand has moved into the screen, an unstable condition has been generated.