This paper is presented to address the issue of the frequent blockage in the D block of Bohai B oilfield, which seriously affected its normal production. Based on the composition analysis of blockage, some laboratory experiments, such as high-pressure simulation of asphaltene deposition, and theoretical prediction of wax deposition and asphaltene deposition phase envelope were carried out. The results showed that there existed a combination of wax deposition and asphaltene deposition in wellbore and asphaltene deposition around near-well zone. Temperature and pressure changes were the main causes. And for that, the treatment strategy of increasing temperature in wellbore and maintaining pressure in formation was proposed. To increase the temperature, the hollow rod electric heating technology suitable for electric submersible pump(ESP) wells was introduced, and the wellhead temperature was raised to above 60 ℃. In order to maintain pressure, the injection-production system was optimized as well. The injection-production system of 7 production wells with 1 injection wells turned into 5 production wells with 3 injection wells and the formation pressure increased from the lowest 72%of the original formation pressure to 94%of that. Two wells that had been shut down for a long time due to blockage in wellbore have resumed normal production, and another two wells produce more than before. No blockage in wellbore occurs again, proving that a remarkable effect is achieved. The research can provide technical reference for the efficient development of oilfields prone to wax and asphaltene deposition, and has important guiding significance.