A Proven Method for the Control of Incompetent Sand Formations

A sand control process has been developed and field proven in the Gulf Coast. The mechanics of the application involve the use of a gel oil (or gel acid or gel water) as a vehicle to carry sand into or against the formation which has, or is expected to, produce sand. This process is carried on beneath a squeeze tool in order to cope with pressures which might otherwise be unsafe. This process makes it possible to pack a formation without mud or water contamination. After the formation is satisfactorily packed, the packing sand is held in place by a screen liner or sand consolidation plastic. Work has been done to determine the most effective packing sands and gravel. Results of this work are analyzed and tabulated. Introduction Sand control problems in the Gulf Coast are as old as oil production in this region. Several sand control methods have been developed; however, there have always been a few wells which defied any sand control measure. It was on wells of this type that the work described in this paper was initially done. Many variables must be considered when the problem of sand control arises. Virtually all sand control measures are dependent on the bridging of formation particles against some screening mechanism placed in the well. This forms a filter which limits the movement of other formation solids into the well bore. Certain basic information is desirable when preparing a sand control program:formation sand grain analysis;variations in sand size in individual zones;formation or producing interval thickness:mechanical hookup of well;subsurface depth of producing zone;degree of cementation of formation;lithology;well fluids to be produced (viscosity);bottom hole temperature and bottom hole pressure;quantity of fluid production; andsand control measures previously used and their success. Some of this well information is difficult to obtain in the Gulf Coast region, due to the difficulty of recovering cores from the poorly consolidated formation.