Study On Damage Mechanism And Workover Fluid Of Carbonate Reservoir In Yubei Block

Repairing completion of reservoir protection in the process of evaluation, good or bad influence makes effect on workover once damage to oil and gas layer, it is difficult to adopt measures to improve in the mine, and operating cost is high. In the process of hydrocarbon reservoir exploration and development, therefore, the systematic analysis of reservoir characteristics and potential formation damage factors, timely and accurately predict the potential reservoir damage mechanism, design and using the reservoir protection of repairing completion fluid, is of great significance for oil and gas field exploration and development. North tarim block YuBei wellblock carbonate reservoir with fracture reservoir, crack-hole reservoir is given priority to, these reservoirs exist in the process of drilling completion drilling completion fluid, acidizing fluid, completion fluid and completion fluid of a large number of leakage, this may cause the reservoir serious formation damage, in addition to this, the carbonate reservoir is caused due to improper completion technology of reservoir damage. In this article, through the experimental study YuBei wellblock potential reservoir damage mechanism is mainly for the reservoir-holes, cracks jams damage, stress sensitivity damage, as well as the water locking damage and other additional capillary resistance filtrate invasion caused damage. According to the characteristics and the storage reservoir potential damage factors, launches to adapt YuBei wellblock of solid free organic salt and workover fluid system. Select suitable for reservoir treatment agent, finally established the temperature resistance, strong ability to resist pollution has a high density of solid free organic salt and workover fluid system (density of 1.70 g/cm3).A great quantity of experiment of interior and field tests make known that the system in original not only keep well rheological, filtration property, the most important inhibitory properties that dissolving to salt and gypsum, Workover fluid scraps'scattering has been effectively repressed, but powerful antipollution (the tolerance to salt, gypsum is at least 10%,1% separately). There are controllable density, lubricating quality and maintained good performance all the time.Indoor experiments show that the Workover fluid system can maintain the well and unchangeable capability. Therefore the research to the system has significant value.