Study On The Favorable Area Evaluation Of Multi-layer Dense Gas Reservoirs In The Overlapping Areas Of Mining Rights And The Deployment Of Clustered Well Locations

Oil,natural gas,coal and sandstone?type uranium deposit were abundance in Ordos Basin.Coal and natural gas formations overlap in the longitudinal direction and also intersect in the plane,due to the mineral?right setting mechanism in mineral?right division legislative system,the interest pattern imbalanced.For a long time,collaborative development of coal and nature gas in multi?mineral overlapping blocks with avoiding the insecure problems is looked at the world's issues,which have long been difficult to study.So far,the research in the academia focused on collaborative explorement technology and lacks to study in collaborative development.Therefore,the coal?natural gas overlapping region is taken as an example to clarify the difficulties in collaborative exploitation and analyze the main controlling factors and distribution pattern of favorable areas in the Upper and Lower Paleozoic gas reservoirs.The technical measures of different areas have been optimized by combining well type?pattern demonstration with efficient drilling?producing and surface gathering?transportation technology to reduce the impact of natural gas development on coal resources and shorten gas reservoir construction and development cycles.This technique has been very successful for the site application.The following conclusions were obtained.We firstly proposed the natural gas development philosophy of "five different concepts?three unite system?overall advance development progress?.According to the principle of?time staggering,space division,safety first,mutual coordination,urgency first",clustering deployment of multi?well clusters should be applied to realize 3D and factory collaborative exploitation of multi?mineral resources.The major technologies of the arrangement of development cluster well groups were analysis technology of gas reservoir master control factor,predicting and zoning technology of gas enrichment area and optimizing technology of well pattern.There develop multiple gas?bearing series in the longitudinal direction of Shenmu Gasfield.Due to the large differences in plane distribution,these gas?bearing series must be subdivided into several blocks,and proper exploitation mode must be worked out for each block.The favorable areas of Shenmu Gasfield can be classified into 4 kinds,Upper Paleozoic sandbody multi?lateral overlapping zone(mainly in the north of the gasfield),Upper Paleozoic sandbody multi?layer overlapping zone(mainly in the center of the gasfield),Upper Paleozoic sandbody isolated overlapping zone(mainly in the south of the gasfield)and Upper?Lower Paleozoic gas reservoir overlapping zone(mainly in the north by west of the gasfield).Combining with drilling and gas production technologies,the 8 well deployment modes were optimized through economic evaluation,which shows 9?well multi?well cluster deployment is the optimum selection with the highest saving of drilling cost.According to the plane distribution of favorable areas in Shenmu Gasfield,and results of well?type and well?pattern optimization,corresponding technical measures have been worked out.Finally,a "multi?well cluster mixed well group development,multi?layer 3D development" mode has been established.Fast drilling technology of multi?well type in big well group?pipeline operation of fracturing model?centralized water supply mode and modular organization were main technologies and mode of drill and fracture.Well to well connection technology for gathering nature gas,integrated skid and digitalize management mode would minimize the impaction to the coal.Practices indicate that the technologies of collaborative development of mineral resources in the same blocks were a new way to solve the multi?mineral overlapping problem.