Beta-Wave Pressure Control Enables Extended-Reach Horizontal Gravel Packs

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper describes a new gravel packing technique for extended-reach open-hole horizontal completions. The method enables gravel packing of long horizontal completions without excessive Beta-wave placement pressure.The physical characteristics of gravel packing horizontal wells have been studied intensively in the past few years. The Alpha-and Beta-wave model has been developed to predict the pattern of sand deposition in the well during the gravel pack operation.The Beta-wave (return gravel wave) placement pressure is the main factor in determining the maximum length of a horizontal gravel pack. This pressure is limited by the requirement to install the gravel pack without exceeding formation fracture pressure, which could result in loss of control of the gravel pack and adverse effects on well productivity.To address the Beta-wave pressure limitation, a new technique has been developed and operationally verified in field installations in the North Sea. The technique uses a special valve, or series of valves, in the inner washpipe that automatically operate to re-direct return fluid flow into the washpipe during placement of the Beta-wave. The valve eliminates the need for the return fluid to travel down the length of the screen to enter through the end of the washpipe. This prevents the accumulation of friction pressure in the screen/washpipe annulus as the Beta-wave propagates from the toe to the heel in the open-hole horizontal section of the well. Strategic placement of these valves in the washpipe string regulates the friction pressure applied against the formation below the fracture limit. Effective design and placement of the valves in the string are made possible with the aid of computational models. The new method essentially eliminates the Beta-wave pressure as a limiting factor in gravel packing extended lateral completions, and makes extended gravel packs possible that would not have been feasible using conventional methods. This paper will describe the concept, discuss the verification-testing program used to validate the theory and review actual field operations that have been performed using this technique.

Multiple Zone Open Hole Gravel Packing Techniques with Zonal Isolation

“…With knowledge of the gravel deposition process and by using pressure actuated diverter valves incorporated into the washpipe, voids can be constructed into the gravel pack at each open hole packer location. 5 The void is accomplished during the Alpha-wave deposition by achieving a fluid velocity of 300 ft/min in the annulus between the open hole packer and the borehole wall. At this velocity, the Alpha-wave dune height is effectively reduced to zero and gravel does not deposit around the packer.…”

“…Horizontal open holes in excess of 6,500 ft have been successfully gravel packed with a brine carrier fluid. 5 Completion Methods #1 and #2 discussed later in this paper absolutely require the use of a brine carrier fluid. Method #3 is suitable for use with either brine or viscous carrier fluids, although brine is preferred.…”

Experimental and Theoretical Simulation of Gravel-Pack Displacement in Extended Horizontal-Offshore Wells

“…Test 16 was performed to evaluate the impact of flow-divergence-valves actuation on openhole pressure. 7 The data recorded during the testing were recorded manually and through electronic-data acquisition. Alpha wave and beta wave transit times were recorded using a stopwatch, starting from the time the sand was started.…”

An Alternative Method of Dealing With Pressure: Friction Reducer for Water Packing of Long Horizontal Open Holes in Low-Fracturing-Gradient Environments

“…Two approaches are used currently to address this concern. One approach involved a mechanical solution using diverter valves that created a short cut for fluid returns, resulting in a reduced wash-pipe/base-pipe annulus as well as wash-pipe length that the fluid has to travel, and thus reduced friction (Coronado and Corbett 2001). Another approach that has been successful is the use of low-density gravel (Pedroso et al 2008).…”