Directional drilling crossing technology in pebble bed geology and equipment optimization

In allusion to the technical problems in crossing pebble bed with heavy thickness and large particle size by horizontal directional drilling, taking the Yellow River directional drilling crossing project of Luoyang-Zhumadian Products Pipeline as an example, the comprehensive construction technology of horizontal directional drilling rig, casing pushing machine and large particle gravel knapper are adopted in the high density pebble bed with the thickness of 38 m and particles size of 80~250 mm. The mathematical model for simulating casing pushing path is presented, and the curve of casing pushing in pebble bed is simulated. And based on the best enter angle determined for pipe pushing, the horizontal directional drilling crossing through the pebble bed with heavy thickness and large particle has been carried out successfully by means of pilot hole positioning jointing system. Considering the influence of ferromagnetism of casing on the ambient geomagnetic field, and then the drillbit's direction of guiding system, the pilot hole positioning jointing System has been developed. The pipe pushing rig especially used for pebble bed crossing is developed based on the common pipe pushing machine and its technical principle. The construction technology in Yellow River directional drilling crossing project of Luoyang-Zhumadian Products Oil Pipeline provides a reference for the similar pipeline crossing project in pebble bed geology with horizontal directional drilling in near future.