Prediction Of Sand Production In Reservoirs Of Keshen Structure Gas Well In Kuqa Block

Sand production is a serious problem in the process of oil and gas production. It can affect production cycle of oil and gas well, corrode down-hole string and surface mining equipment, and block the reservoir production wellbore due to sand cave, thus these would influence the yield of oil and gas well in different degreesand cause series of serious consequences such as reservoir damage, even more it may affect the failure-free operation of the whole block. Therefore, it may have great significance for guiding the efficient development of oilfield to study the mechanism and affecting factors of sand production.Block Kuche, with its superiorpetroleum geologic condition, rich oil and gas resources, is one of the three biggest ultra-deep, high-temperature and high-pressure oil gas areas in the world.The reservoirs mainly are siltstones and fine sandstones with the sandstone reservoir characteristics of fracture, low porosity and permeability and poor physical properties. Seen from the pictures of the two typical sandy wells on site, both the two wells would suffer from sand production.Firstly,analyzed the reservoir geology and physical properties of Cretaceous Bashijiqi Formation in Keshenof Block Kuche,it could be concluded as follows:The reservoirs of Bashijiqi formation is the tight sand, which mainly are siltstones and fine sandstones with low porosity and ultra-low permeability. Then we analyzed the two typical sandy wells in area. Through the rock mechanics experiments, we got rock mechanical parameters, such as the rock elastic modulus, Poisson's ratio,compressive strength. After calculation and contrast, the calculated ground stress considered the strata dip is much closer to the true value. Based on the result, it can be known that in the reservoir of the K-1 well and the K-2 well, the maximum horizontal principal stress SH?vertical stress Sv>the minimum horizontal principle stress Sh, the formation belongs to the strike slip type. Created prediction models of the perforation completion wellhole surrounding stressand the four critical bottom hole pressures, and analyzed the parameters. In order to verify and optimize the critical bottom holepressure model suitable for studying the area, we analyzed the sand prediction of the two typical sandy wells (K-1 well, K-2 well) in area, the results are as follows:In the K-1 well, the reservoir section has a slight sanding production when using the D-P model, which is in line with the reality; While in the K-2 well, the reservoir section has a severely sand production both using the D-P model and the comprehensive strength model, which also fits the reality. Thus, it is better to choose the D-P model as the best prediction model for studying the sand production in areas. Besides, it is not applicable when using the combined modulus method to predict the sand production of the ultra-deep, high temperature andpressure reservoir, while the D-P modelcan accurately predict the sand production. In order to accurately and fast calculate and analyze the sand production in reservoir, this thesis has made a set of evaluation software using Visual Basic programming language based on the sand producing mechanism, which not only can calculate the rock mechanics parameters depending on the well logging data and preferred models, but can predict the ground stress, the hole surrounding stress, the critical bottom hole pressure and the reservoir sand production, moreover, we analyzed the sand production of the two typical sandy wells and the results showed it matched the reality. Thus, the reservoir sand prediction software in the paper has certain practical application value.