Gravel Packing High-Volume Water Supply Wells

Abstract

The successful installation of sand control in four wells in the Berri field, Saudi Arabia, is discussed. A combination of underreamed openhole gravel packs, large diameter equipment, and proper field selection provided rates of over 80,000 BOPD with less than one-half ppm sand production. The paper explains the initial sand production problem and sand control in these wells. Introduction Openhole gravel-pack completions performed in four new water supply wells in the Berri field have proven successful in greatly reducing the sand content in the produced water. The wells are located on Abu Ali Island at the northern end of the Berri field, Saudi Arabia. These new supply wells, and the existing wells, provide water for the water injection program at Berri.Sand production was found rate sensitive when the first supply wells were tested at Berri with levels as high as 150 ppm at rates in excess of 80 MB/D (12 700 m3/d). This level of sand production is short-lived and the level declines to as low as 4 ppm after several hours of stabilized flow at 80 MB/D (12 700 m3/d). Ten of 19 wells require restriction orifices due to increased sand production at higher flow rates. Sand producing levels have tended to increase at constant production rates indicating an increase in sand producing characteristics with time (see Fig. 1).An extensive testing program was conducted to determine the detrimental effects of the produced sand. Originally it was believed that a sand level of 15 ppm could be tolerated through centrifugal pumps at the Berri injection plant. However, within a period of 6 months there were seal and throttle-bushing failures in the pumps due to erosion by sand. Erosion damage was noted also on the impellers and pump casings. In addition, sand was collecting in the gathering lines. It was also noted that at 100 MB/D (15 900 m3/d) the stabilized sand production tended to be above 10 ppm.Since the test data indicated that damage to the water injection plant was severe at a sand production level of 15 ppm, a level of 3 ppm was set as the acceptable upper limit. However, in spite of efforts to monitor the sand, it continued to cause or contribute to pipeline failures in three ways:erosion of the bottom of the pipe,erosion of the inhibitor film resulting in pitting, andcorrosion as a result of sand and inhibitor deposits on the bottom of the pipe. The water injection wells required workovers to remove sand and corrosion products and stimulation treatments to repair the formation damage caused by the fill. Plans were made to install submersible pumps in these source wells when they would no longer flow at reasonable rates, however additional damage to the equipment was anticipated unless sand could be controlled downhole. Because of the problems with produced sand, the decision was made to openhole gravel pack the water source wells as a means of controlling sand. Four test wells were selected for a pilot program to evaluate the feasibility of gravel packing in these high-rate conditions. The test program was also designed to evaluate the procedures and equipment used in these completions. JPT P. 2097＾