Study Of Oily Sludge Profile Control Technology On The Themal Wells Of Cyclic Steam Stimulation

It's easy to result in serious uneven steam absorption and even steam channeling after several cycles of steam stimulation due to the heterogeneity of heavy oil reservoirs and the characteristics of steam overburden,which results in poor recovery and low economic benefit,so it's necessary to have a profile control on the cyclic steam stimulation reservoir.Oily sludge profile control technology is the technology of rejecting oily sludge to formation to enhance the reservoir recovery,so oily sludge profile control technology can reduce the oily sludge processing costs and it can also play an important role in reservoir profile control.In order to solve the severe steam uneven absorption problem and even steam channeling,oily sludge profile control technology is put forward.The major content of works are as follows: First to study formation properties regularity in the process of steam stimulation and reservoir steam absorption regularity through reservoir numerical simulation.At the same time,study characteristic of oily sludge and blocking ability of oily sludge and profile control effect through the indoor experiment;Then,based on the results of laboratory experiments,the numerical simulation model of oily sludge profile was builded and the profile control effect of oily sludge through laboratory experiments;In combination with the results of laboratory experiments and reservoir numerical simulation,the profile mechanism of oily sludge is proposed,and the experimental evidence is put foreard to prove the profile mechanism of oily sludge.Finally,the influence of profile design and profile parameters of oily sludge on the profile control effect of oily sludge is also studied.Study find the permeability and pore in the formation will have a big change during the cyclic steam stimulation,and the change of pore and permeability will also influence the steam injection pressure and production performance.Permeability heheterogeneity is the most important factor for steam channeling problem of oil reservoirs.Blocking experiment research show that oily sludge has a strong blocking ability,it also found that the permeability and temperature had a great influence on the oily sludge blocking performance;The results show that the oil sludge has a good effect on improving the oil displacement efficiency.The numerical simulation results show that the oil sludge can improve the uneven absorption of the reservoir and improve the recovery rate of oil reservoirs,which indicates that the oily sludge has a good profile control ability.Oily sludge profile control mechanism mainly includes two aspects,on the one hand,oily sludge has a big physical blocking ability in the way of“oil mud”and adsorb,on the other hand,the oily sludge has the nature of the blocking high permeability channel to achieve selective blocking ability;Oily sludge profile control technique and parameter studies have shown that injecting oily sludge to high permeability zone injection,to inject oily sludge at an early time,oily sludge injection temperature is 100? can produce better oily sludge profile control effect,and proper injection volume of the oily sludge following with different reservoir conditions was studied,and application suggestions for the on-site application of oily sludge in oil field were also put forward.