Key Drilling Technologies for Long Displacement Horizontal Wells of Low Permeability Reservoirs in Shengli Oilfield

Drilling long displacement horizontal wells has become an important technical support to develop low permeability reservoirs,but related techniques in China start relatively late.It is necessary to reach a common understanding of the techniques and carry out further research on optimized match drilling techniques.Therefore,the key-point of the technique has been identified by analyzing their difficulties in well trajectory design and control as well as drilling fluid properties.The principles for selection of build-up rate and well trajectory type have been set up through simulating torque and drag.Through analyzing sensibility of friction coefficient and displacement from well head to target point,the main characteristics and their relationship have been determined,the corresponding explanation of drilling string mechanics was given,the selection principle of displacement from well head to the target point was proposed,the main idea for well trajectory design of long displacement horizontal well formed.An optimized well path control solution was established on the basis of formation drillability grades,and then an effective well path control method was presented by rotary reduction of friction.The critical techniques of wellbore stability,hole cleaning and anti-stick lubrication were sorted out and introduced.Well Gaoping 1 is taken as an example to illustrate the above techniques and their effectiveness.