Research On Drilling Speed-up Technology Of Horizontal Wells In Chepaizi Well Area

Horizontal wells have significant economic value in oil and gas reservoir development,and they have become the main drilling method for oil and gas reservoir development.Although the exploration prospects of the Carboniferous in Chepaizi Block are good,factors such as long drilling cycle,slow rig drilling speed and frequent occurrence of lost circulation conditions severely restrict the exploration and development speed of the Well 471 area.By collecting the data of well logging and logging in the target area and the related data of geology,development and drilling,the distribution of regional structure can be grasped macroscopically;the collected data can be classified and sorted out,and the distribution of complex strata in the area can be statistically analyzed.The geological characteristics and difficulties of drilling in the target area are given,and the complex prevention countermeasures are formulated.According to the results of in-situ stress test and in-situ failure test,the present state of in-situ stress is determined.Based on this,the in-situ stress model and three pressure profile of well Che 471 are established,which provides theoretical basis for well bore structure optimization.Through in-depth analysis of the engineering geological factors affecting the optimization design of the well bore structure,optimization of the well bore structure of the horizontal well and simplification of the casing procedure,a relatively mature well bore structure of the second spud in well block Che 471 has been formed.Aiming at the complexity of formation characteristics,formation pressure system evaluation results,collapse,diameter reduction,and leakage,combined with the problems of differential pressure sticking and casing that may occur during the optimization of the wellbore structure,the corresponding cement slurry is designed to be effective Has controlled the formation pressure system to be in a balanced state,reduced the complex accident of lost circulation,and achieved a good effect of preventing differential pressure sticking and casing sticking.For the Carboniferous strata with low ROP,combined with laboratory experiments,a study on the evaluation of formation rock mechanics characteristics was carried out,a comprehensive bit type selection method was integrated,and a bit sequence suitable for different formations in the Che471 area was explored.In this paper,combined with actual working conditions,complex technical measures for prevention are given to reduce the amount of drilling fluid loss and the rate of complex drilling time.Using the vertical and horizontal bending method to analyze the combined force of the single-bent screw drilling tool can obtain the results of the lateral force and dip angle of the bit,and optimize the weight-on-bit parameters and screw bending angle,which can effectively control the well deviation.Affected by the position of the deflection point,the slope of the well may cause the failure of the drilling tool body.The failure position of the deflection point is adjusted appropriately to prevent the failure of the body through the analysis of the failure of the drilling tool body in the deflection section.Through the research of this paper,the supporting technology of horizontal well drilling and speed-up matching with Chepaizi well area is finally formed.The optimized second-open wellbore structure realizes the large-scale application of regional wellbore structure design;the drilling fluid and cement slurry system effectively controls the formation pressure system to be in a balanced state to ensure the smooth progress of drilling and cementing operations;The screw combination and corresponding drilling parameters matching the corresponding formation are given.After on-site application,the average drilling period was shortened from the previous 76 days to the current 47 days,a reduction of 38.15%;the average ROP of the horizontal section increased from the previous 3.84 m / h to 4.64 m / h,an increase of 20.8%;The average ROP of the well section increased from 6.82 m / h in the previous period to 8.69 m / h,an increase of 32%.The application of drilling speed-increasing technology for horizontal wells in Che 471 well area provides guarantee for the economic and efficient development of horizontal wells in the entire block.