Analysis On Factors Affecting Repair-free Period Of Rod Pumping System In Tahe Oilfield And Research On The Correspongding Countermeasures

Tahe oilfield is a typical heavy oil reservoir with characteristics of large crude oil viscosity,deep depth of plunger and a large number of application of the unconventional pump—hydraulic feedback pump in the oil extraction process.Due to the particularity of Tahe oilfield itself,in the process of application of sucker rod pump in production,it has been found that repair free period has been continuously shortened,failure frequency of pumping unit has gradually increased in recent years.Therefore,in this paper,it makes an in-depth analysis on the pumping system in Tahe Oilfield,finds out the key factors of the system failure and puts forward the countermeasures.First of all,based on a lot of field data and authoritative expert opinion,FTA is used to analyze rod pumping system of Tahe oilfield qualitatively and quantitatively,and the conclusion shows that the system failure high risk parts are pump inlet valve,pump plunger and sucker rod.Secondly,the main reason for the failure of inlet valve is found by comparing the conventional pump inlet valve and the experimental study of ball-bonnet.The structure and material of the hydraulic feedback pump are innovatively optimized.The field test achieved good effect.Moreover,according to the characteristics of hydraulic feedback pump,analyze friction between plunger and pump barrel and the interval leakage situation,obtain the new model of optimum pump clearance which is appropriate for hydraulic feedback pump by power loss method;calculate and come up with the optimum clearance level design approach.At last,seek the root cause of rod broken by test detection and theoretical study,make suggestions on rod broken prevention,optimize design proposal of hydraulic feedback pump system and provide a reference for field application.