Investigation on Sand Production Problems and its Mechanisms

Sand production is a common complex problem during oil and gas exploration and it's one of the principal challenges in different steps of field expansion planning including wellbore stability during the drilling. Sand production leads to several damages and disadvantage such as surface and down hole equipment erosion, wellbore damage, equipment failure, small maintenance-free periods and obstruction of valves is typically suffering for this in the form of erosive damage for oil and gas explorers especially companies producing from unconsolidated formations. One of the main tasks of exploration in the oil and gas industry is strengthening and stabilization of production. However, the main problem for arriving atthe this purpose is that most of the formations around the gas and oil wells, especially reservoir formations consist of highly unconsolidated sand grains and the other problem is the rock failure during wellbore drilling and perforation as well as hydrocarbon production. Therefore, production is complicated due to entering of sand to the wellbore because of several reasons such as stress concentration around the borehole, increasing of water production levels, production flow increasing, drawdown pressure increasing and passing of this pressure from a critical level and etc. Accordingly, there is great interest to estimate the critical conditions that the rock failure occurs and sand migration is beginning. In fact, rock failure and sand production prediction can be done by using of petro physical logs such as sonic logs, tectonic stresses information and geodynamics data. The estimation advantage of rock elastic parameters, pressure and stress properties and rock mechanical properties to calculate the rock strength and sand production prediction from existing logs is recognized as the real and original condition of the measurements.