Optimizing Friction Reduction on Motor-Steered Bottomhole Assemblies: Harnessing the Power of Multiple Shock Tools as a Cost-Effective Solution

Enhancing drilling efficiency while minimizing costs is crucial. Effective friction reduction in conventional motor bottomhole assemblies (BHAs) is key to achieving this. Friction reduction technologies (FRT) modify the total flow area to create high-frequency pressure pulses, generating axial oscillations at the shock tool (ST). This paper explores the effectiveness of integrating multiple STs within the drillstring to enhance performance. Empirical evidence supports their role in improving efficiency, extending lateral length, and reducing operational costs. FRT typically consists of a power section and valves (PSV) and an ST. Pump open force (POF) at the ST, applied by pump pressure during circulation, is crucial. The pressure differential across the ST housing determines the POF. For optimal performance, ST placement above the PSV is ideal, as this location maximizes pressure amplitude. The residual pressure pulse can activate additional STs, expanding the agitation zone. STs contain a spring stack that manages axial vibration under typical conditions. Strong pressure surges cause the mandrel to extend, while pressure relief enables spring reset, ensuring continuous mandrel motion. Pressure waves from the PSV propagate through the FRT, and their magnitude degradation depends on factors like drilling fluid rheology and well profile. Strategic ST placement ensures sufficient pressure wave magnitude to activate other STs. Field data from South America highlights the importance of pre-job planning and thorough data analysis. Adding extra STs enhances axial oscillations, improving weight and torque transfer without significantly affecting standpipe pressure. Analysis of the data has revealed the significant positive impact that additional STs have had on operations. To fully assess the weight of each contributing factor in optimizing drilling performance, such as spring stiffness, drilling parameters, pressure drop across the PSV, and the distance between the FRT and additional ST, larger data density is warranted.