Engineering and Operational Efforts Reduce Sucker Rod Failures
Authors: Mueller S.E. , O'Neil R.K. 
Published: December 2007

This paper was prepared for the 44th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Denver, Colo., September, 28-October 1, 1969. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
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Abstract
This paper reviews the remedial program utilized in the South Glenrock "B" Unit waterflood to lower the sucker rod failure rate, which was rapidly accelerating due to increasing well loads and changing environmental conditions. Through a program of rigorously controlling joint makeup, magnetic particle inspection of joints and coupling replacement the rod failure frequency was reduced 70 percent in two years. The program has resulted in significantly lowered operating costs, increased production and improved utilization of company manpower.

Introduction
The South Glenrock Field is located on the south edge of the Powder River Basin, which has undergone a very active development in the Muddy sand in the last two years. The field was discovered in 1951 and development was essentially complete by 1954 with 193 wells within the present unit boundary. Production is from the Cretaceous Muddy Production is from the Cretaceous Muddy and Dakota sands, which occur at 5700 feet and 7450 feet, respectively. The majority of the wells were cased through with 5 1/2 inch casing and were initially equipped with 2 3/8 inch tubing and 3/4-5/8 inch rod strings.
The South Glenrock "B" Unit was formed in 1961 to waterflood the four benches of the Muddy sand and Dakota sand reservoirs. Production from all reservoirs was Production from all reservoirs was commingled in the wellbore during both primary and secondary operations in spite of the fact that only the Dakota and Upper Muddy reservoirs were initially flooded. Water injection was segregated by reservoirs. The field is representative of many of the problems that can be anticipated in future waterflooding in this basin.
As noted on Figure 1, it can be seen that the initial response was in March, 1963 and that by December, 1966 the total fluid withdrawals reached 26,100 BPD. Of this, 14,705 BPD was being lifted by 96 rod pumped centrifugal pumps. Figure 2 shows the average daily producing rate per well of the rod pumped wells only. per well of the rod pumped wells only. As the total fluid withdrawals and the associated rod loads increased, the sucker rod failure frequency increased.