Experimental Study On Sand Control Technology Of Bohai 76 Block

The sand production refers to the phenomenon that the sand particles in the stratum are transported out with the production fluid.The nature of the sand production is attributed to the overpressure of the formation pressure.The effects of sand production mainly include the wear and corrosion caused by wells and wellhead oil extraction equipment,shortening their service life;the instability of the wellbore causes the casing to collapse and the well to be scrapped;resulting in a decrease in production or production suspension.The most important element of the sand control method is to prevent sand particles from being brought into the production fluid by the fluid.At present,sand control methods can be divided into mechanical principles,chemical effects,and sand body sand control.For the contacted cemented shaly sandstone strata in Gudao Oilfield,the shaly components of the contacted clay shale can easily fall off after being washed,resulting in the collapse of the rock skeleton in the strata.This article has done the following work in the sand control of the Gudao Fen 76 fault block:(1)Basic understanding of reservoirs.According to the study,the pore distribution of the reservoir in Bo 76 is uneven.The petrological characteristics indicate that the fault block is a coarse and coarse Xihe sedimentary sandstone.The average porosity is between 28.45% and30.5%.(2)Sand control technology.The structural alteration of the reservoir in the heavy oil adjustment area of the Bo 76 fault block is very loose,and sand is easily produced during production.The reservoir rock is dominated by fine sandstone and siltstone.Study to determine the size of straight slope inclined wells filled with sand control gravel,including Ng1+2 layer selection 0.3mm ~ 0.6mm,0.4mm ~ 0.8mm gravel,Ng4 layer selection 0.4mm ~0.8mm,0.6mm ~ 1.2mm size gravel.The clay stabilizer(HCS,BC-61)was used to reducethe migration of particles.Reverse washing with earth acid performed deblocking on the damaged formation.(3)Experimental research on sand control technology.Two experimental studies were conducted on sand control gravel and oil sand production.The research on the seepage ability of sand-control gravels shows that the clay-free,clay-bound and post-sanding seepage capacity is studied.The gravel particle size is 0.3-0.6mm,the clay content sensitive point is 10%,and sand migration in the near well area should be controlled.The sand production study shows that when there are two kinds of oil and water in the core,the higher the water content is,the higher the viscosity of the fluid is,and the easier the sand grains are brought out.When the core water content is 29.5%,the sand control effect is obvious.The core experiments show that the gravel with particle size of 0.4-0.8 mm has the best sand control effect,and the larger the filling thickness,the stronger the sand filtration capacity.On the basis of experimental verification,the on-site application of pre-filled double-wrapped sand control technology was carried out.The construction process,formation treatment,gravel parameters,and sand control columns were optimized,and two wells GDB79X9 and GDB76X50 were used as examples for analysis.The investigation shows that the daily liquid level of the block is around 360,the daily oil level is 110,the production cycle is extended from 300 days to 701 days,and the sand control effect is obvious.This achieves the expected goal of the study of this paper and provides a reference for the economical and effective development of the oil field.