Design And Application Of Hydraulic Pulsed Jet Generator Based On The Research Of Fluctuation Of Weight On Bit In Vertical Well

Enhancing the penetration rate is very essential to accelerate the exploration and production of deep hydrocarbon resources.The factors that lead to the slow penetration rate of deep wells are various,including the lack of hydraulic energy on the bottom and low energy utilization efficiency which are the important reasons.To strengthen the downhole hydraulic energy and improve energy utilization efficiency,a new idea of modulating the pulsed jet by the energy of drilling string vibration was put forward in this paper,with consequently Drilling String Absorption & Hydraulic pulsed jet generator(AHPJG)designed.The new generator that transforming the energy of drilling string vibration into downhole hydraulic energy and modulating the continuous jet of drilling fluid to pulsed jet,not only can strengthen the downhole hydraulic energy and improve the utilization efficiency but also avoid the harm caused by drilling string vibration,implementing the optimal combination of the bottom hole mechanical energy and hydraulic energy so that the distribution of bottom energy becomes more reasonable,provides strong support of equipment for safe and efficient penetration in deep wells and ultra-deep wells.By the utilization of drilling string dynamic simulation experimental apparatus under the absorption of vibration,basic experimental study under different conditions of characteristics for WOB and drilling string longitudinal vibration is carried out.Based on the acquired basic experimental data,the energy of the normal and absorption of vibration conditions in the drilling string vibration process are calculated respectively,and the influence of different experimental parameters on the energy conversion efficiency of drilling string vibration are analyzed,which build a foundation for reasonable and efficient utilization of energy of drilling string vibration.On account of the results of that research,to carry out optimized design of structure for Drilling String Absorption & Hydraulic pulsed jet generator(AHPJG),the numerical simulation model is established through the analysis of the principle of that generator,which carry out the feasibility analysis from a theoretical point of view.By the simulation model of Accessing to the functional relationship between structure parameters and working performance,the objective function and constraint conditions have been established.The optimization of structure parameter based on ant colony algorithm,the design of incentive piston valve and the strength check of key components are carried out,which conduct the collisionless detection of three-dimensional model and analysis of the coordination of the generator by using of CAE technology.Aimed for the incentive piston valve invalidation of erosion problem in the process of field test,invalidation mechanism analysis is made that aims at the invalidation problem of incentive piston valve,basing on the CFD fluid mechanics,and targeted structure optimization design is put forward that aims for the structure factors which led to the incentive piston valve invalidation.Performance assessment about the incentive piston valve after the structure optimization is made,using fluid mechanics analysis method and the field measurement method and results show that valve body which have been optimized has a more reasonable inner fluid structure,lower pressure loss,and the critical factors which easily lead to erosion have been restrained after optimizing and the longevity and properties of incentive piston valve may meet the spot operating requirements of Drilling String Absorption & Hydraulic pulsed jet generator(AHPJG).The equipment,after passing though ground performance testing-which guarantees safety reliability-and its working parameters being optimized basing on simulation analysis model,have been tested in more than ten oil wells of many oil fields.Results show that the equipment can enhance drilling speed above 30% in general,protect drill bits effectively,prolong the service life of drill bits,and the equipment's service life may meet the spot operating requirements.Results also show that the equipment may fit exiting operating conditions with no specific requirements about drill bits and no disadvantages about drilling operations,and it may enhance drilling speed more effectively in brittleness and hard formations such as conglomerate formation and sandstone formations and so on.