Research Of Field Test To Prevent And Control The Sleeve-Pipe Damage Wells In The Third Fault Block Of Pubei Oilfield

Along with the development of oilfield, the distortion and damage of the sleeve-pipe of the oil and water wells has seriously affected the normal production of crude oil, and caused a serious threat to the oilfield sustainable production and huge economic losses also. Since 1978, when Putaohua oilfield began to been developed, 169 oil and water wells have been invalidated and 270 wells are being operated with faults due to the sleeve-pipe damage. Moreover the amount of sleeve-pipe Damage wells has been increasing at 20-30 annual rate. The North of Putaohua oilfield, namely pubei oilfield is the most serious area of sleeve-pipe damage in Putaohua oilfield. At present, the sleeve-pipe Damage wells amount to 335, and account for 75.11 percent of Oil product No.7 of daqing oilfield, the third fault block is the main sub-area of sleeve-pipe damage in pubei oilfield, the rate of sleeve-pipe damage is higher, the rate of sleeve-pipe damage of based well network has added up to 44.3 percent. The sleeve-pipe damage has become important factors to restrict oilfield development efficiency.By classifying and analyzing the sleeve-pipe damage wells of the third fault block in Pubei oilfield ,this article has studied the distribution of sleeve-pipe damage wells in longitudinal, horizontal and type, and the lithological characteristics of damaged part. It is discovered that the sleeve-pipe damage wells mainly distribute in the mud shale stratum within and above the perforated well sects in longitudinal. the sleeve-pipe damage wells in the plane still mainly distribute on both sides of faults, the large expanse of damages are in the partial region. The damage point lithological character is the mudstone primarily. According to the distribution and characteristics of sleeve-pipe damage wells, this article has analyzed the primary reason to cause damage of different types, different parts of sleeve-pipe, and discussed mechanism to cause sleeve-pipe damage. It is thought that many reasons can cause the distortion and damage of sleeve-pipe, e.g. geological factors, engineering factors, corrosion factors, and so on, but in essence, all are caused by the lopsided pressure. The stratum pore pressure forecasting technology is the key to control the stratum pressure in reason. Through the screening analysis, it has been determined to forecast the stratum pore pressure by three curve technique, so as to adjust the pressure distribution condition by combined with oil-field development actual condition and using the method of irrigation structure adjustment, the decompression measure, plane pressure adjust, and so on, which enable the plane, the longitudinal pressure to tend to balance, thus eliminated the hiddentrouble of sleeve-pipe damage. The effect is obvious, it will provide the theory basis of sleeve-pipe protection work for future。...