A Study of the Properties, Installation, and Performance of Sintered Metal Gravel-Pack Screens
Authors: Cole R.C. , Arterbury B.A. , Taylor R.W. 
Published: October 2008

The new technology of porous sintered metal screens (PSMS) addresses the two major causes of well screen failures; impact damage and erosion cutting. This technology shows promise in reducing screen failures and may help save money by reducing the number of workovers made necessary by these causes. Prototypes of thin-walled PSMS have been tested for (1) tendencies toward corroding and scaling, (2) cleanup by backflushing, and (3) installation through 90 degree bent casing. It appears that PSMS offer some improvements over conventional prepack screens for gravel packing. fie advantages to the @SMS) over thin-wall designed prepack screens (TWPS) were found to be (1) uniformity of the porous metal screen media compared to sand, (2) resistance to damage caused by handling, and (3) properties that allow it to be cleaned up quickly and thoroughly by backflushing.

In addition to a discussion of the above findings, this paper presents results of actual installations and performance of PSMS units in producing wells.

PSMS have dimensions similar to those of prepack design screens, having a thin filter media layer. This affords more annulus clearance to help assure adequate gravel placement and retreivability.

INTRODUCTION OF POROUS SINTERED METAL sCREENS (PSMS)

Porous sintered metal technology has been applied to the manufacture of gravel pack screens for oil and gas wells. PSMS consists of a porous sintered metal jacket bonded to a conventional, offset-drilled base pipe. This screen retains the advantage of the thin-wall design concept in that the sintered metal jacket takes up little more annulus space beyound the base pipe than do the wires on a conventional wire-wrapped screen. Perhaps more importantly, the PSMS offer a solution to the major failure problems that plague thin-wall design prepack screens, Impact Dammze and)?laws in the preuack Sand Layer.

The jacket of a PSMS is normally about 0.15 to .25 in. thickness and continuous strength and porosity. So therefore, if the outer few grains of sintered metal become damaged by impact, the inner particles remain locked together in their original configuration. This avoids localized" pore opening leading to a channel. The adherence and ductile properties of the porous sintered metal of PSMS make it capable of absorbing normally catastrophic impacts without creating a point for later erosion attack or of pore closure.

Although the powdered metal particles are randomly shaped, a high degree of flow uniformity in the sintered metal jacket is achieved by relative size uniformity of the powdered metal and in the way in which particle to particle pressurization is used before sintering. The powdered metal used has a gnarled and twisted shape, but haa strictly controlled particle size, this in part, contributes to the reproducible properties of the sintered metal matrix. Figure 1 shows the typical shape of the powdered metal used. Because of this control, the user is more certain to have a reliable filter medium at all points along the PSMS, without grain settling or shifting.