Optimization Design And Application Of Horizontal Well In Land Faces Shale Oil And Gas Of Biyang Depressed Area

Along with the development of economic and increasing demand of energy, The exploitation and development of Shale gas is a central issue over the word. Horizontal well technology is the mainstream of the current development of shale gas. But shale swells in water. This will cause the diameter decrease of well, even cause the wall collapse. So there are a lot of higher technical problems in the exploitation of shale,such as well depth structure, borehole trajectory control, drilling fluid optimization, drilling safety etc. These issues bring great difficulties to the construction. The exploitation and development of Shale oil and gas of Biyang depressed area is an important measure to secure more reserves. The optimal design and application of horizontal well is the key. Therefore, corresponding research about the drilling technology of horizontal well in land faces shale oil and gas of Biyang depressed area can provide technical support for the construction for horizontal wells of shale oil and gas in Henan oilfield.This topic is based on geological characteristics in Land Faces Shale Oil and Gas of Biyang depressed area. From well structure, well profile and engineering three aspects, optimize the horizontal well of Biyang shale oil and gas in Henan oilfield according to the experience and methods of the design about shale oil and gas horizontal wells in domestic and foreign. The topic also designs and optimizes the third-open wellbore structure of the shale consulting the horizontal well both in domestic and international and drilled wells(vertical well) of land faces shale oil and gas in Biyang depressed area. Using Landmark software Compass module to design the well bore profile and well plan module to calculate friction torque of the wellbore profile, after well structure being given, optimize the well profile to straight wellbore- build wellbore- hold wellbore- build wellbore- horizontal wellbore, which have the smallest friction torque in the tripping out, tripping in, slide drilling and combined drilling.Basing on the application analysis of build-up rate and the screw size of the high-inclination well in Henan oilfield, optimized the build-up rate, screw size which are suit for horizontal wellbore of land faces shale oil and gas of Biyang depressed area and optimized the BHA to control the well trajectory which are suit for vertical well and sidetracking period.Researched and analyzed the application of the drilling fluid of the shale in the domestic(vertical well), international and the drilled well of land faces shale oil and gas of Biyang depressed area. According to the strata characteristics of horizontal well and the designed well structure of the third open, the optimum selecting for the initial open is a leak-proof bentonite polymer drilling fluid system. Pilot hole section will take zwitterionic polymer drilling fluid system with strong inhibitory and good carrying capacity. The directional deflecting second section will use zwitterionic polymer oil-mixture drilling fluid system with excellent filtration property, inhibition, lubrication and suspension ability. For the technical problems which exist in third-open on shale about horizontal drilling, researched the oil-base drilling fluid system and the optimization of formula which are suit for the horizontal well, optimized the drilling fluid, water, oil/water ratio, emulsifier, wetting agent and other additives, formed the suitable oil-base drilling fluid formulation for horizontal well in land faces shale oil and gas of Biyang Depressed area. Evaluated and analyzed the inflation rate, recovery rate, resistance of drilling cuttings and sealing performance of the formula.Analyzed the possible problems in the drilling of shale oil and gas horizontal well and developed the corresponding technical control measures from these aspects: the drilling tool failure, the friction loss and complicated conditions of the down hole.Based on the design of horizontal well, successfully constructed the first horizontal well of shale oil and gas in Biyang depressed area(Biye HF1 Well). The design is conformed to the actual operation. The good effect, initially formed design and related technical measures of the shale oil and gas horizontal well in Biyang Depressed area can provide technical reference for later similar wells.