复杂结构井工厂相关钻井优化设计基础研究进展OA

A complex-structure well factory is fundamentally characterized by three-dimension,multi-function,and multi-type cluster wells.This well factory plays a vital role in the efficient and green development of unconventional energy and mineral resources,such as shale oil/gas,coalbed methane,oil-rich coal,deep coal,and geothermal energy.However,the construction of complex-structure well factory involves the coupling effects of multiple factors(e.g.surface conditions,geological characteristics,and engineering parameters),making the optimal drilling design with multiple parameters under multiple constraints quite challenging.This paper elaborates on the theoretical connotation and development status of the complex-structure well factory,focuses on research progress and recent achievements in drilling optimization design,and finally presents several suggestions for future development.The following results are obtained.First,the extension limit prediction for extended-reach directional drilling has evolved from a single-aspect approach to a multi-dimensional method incorporating mechanical,hydraulic,and open-hole aspects,while the focus has expanded to engineering optimization design under the constraint of the limit.Second,the optimization design of well factory platform layout has advanced from single-objective,two-dimensional planar design to multi-objective,three-dimensional spatial design incorporating factors such as drilling limits and costs.Third,the optimization design of three-dimensional cluster trajectories has developed from single-objective optimization with few constraints to multi-objective optimization considering more constraints,including total drilling footage,engineering costs and operation difficulty,and has expanded from single-trajectory optimization to cooperative optimization of multiple trajectories.Fourth,the design of wellbore structure and casing strength has transitioned from deterministic to probabilistic methods,and from considering fewer operating conditions to considering more.In conclusion,the complex-structure well factory is evolving toward larger scales with denser three-dimensional trajectory distributions.Drilling design methods are at an important development stage,transitioning from conventional mechanistic methods to data–mechanism hybrid methods.In the future,research should be strengthened in geology-engineering integration,design-control integration,as well as digitalization and intelligence,so as to provide support for the innovative development of fundamental theories and key technologies for the design and construction of complex-structure well factory.