Sand production from unconsolidated formations in oil and gas wells has been a world-wide challenge for the petroleum industry for many decades. The challenge is not merely to avoid or stop sand production, but to be able to maintain commercial well productivity after efforts to control sand are implemented. At the same time, the control method selected must be justified by a reasonable payback time of the investment cost.
Produced sand is a major problem in many production situations since small amount of sand entrained in the produced fluid can result in significant erosion and erosion corrosion problems. Even in "sand free" or clean service situations where sand production rate is only a few pounds per day, erosion damage could be very severe at high production velocities. Sand erosion can also cause localized erosion damages to protective corrosion scales on pipe walls and result in accelerated erosion-corrosion damage. In a high velocity gas well sand erosion is a serious problem since it can erode holes in the pipe work in a very short time period1.
Produced sand can result in serious damage to the reservoir, where in some cases the reservoir collapses as a result of the sand production. Again, this scenario is a costly experience for the operator who has to overhaul and complete the producing reservoir zone.
In this paper, we will present the optimum procedures for calibrating ClampOn sand detector which will help us to detect sand production. Also, we will present the effect of water production and choke change in the sand detector response.
Control of sand production is a major concern in Sun Gas Company's offshore Gulf of Mexico operations. Sonic sand detection systems now in service on several Sun operated production platforms provide effective, relatively low cost platforms provide an effective, relatively low cost method for maintaining optimum production rates while minimizing equipment erosion and well bore damage. A case history of field application on one Sun platform as well as the theoretical basis for the Sonic Sand Detector is presented2.
The major advantage of using the ultrasonic sand detector to detect sand is that sand monitoring has moved forward from a level of production trend to actual quantification in real time. The detector quantifies sand beyond its initial limit of profiling. The principle adopted uses an iterative method to locate a considerable threshold in the sand signature logged. Raw signals, in energy/sec, were simulated to reflect true sand production by marking up the background noise value, with about 10% to achieve the true sand free level of the signals for sand rate calculation3.
Some of the lessons learnt from the application of the DSP Sand Monitor are; a single sample from a shakeout (Wellhead Sample) may not represent the true sand characteristics of a well. Average sand reading from the monitor should not be expected to match a single value shake out. Successful use of monitor requires teamwork and coordination among petroleum engineers (PEs), Operators4.
