During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such ...During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such as deep burial depth (>2000 m), thin coal sweet spot (3 m), and significant short-distance structural fluctuations. The challenges caused a high risk of missing targets and running out of the target layers, as well as difficulties in cementing and completion due to uneven well trajectories. To address these challenges, this paper focuses on solving the issues through detailed precise geological modeling, optimized trajectory design, and accurate seismic geology Steerable Drilling. 1) Based on reasonable velocity field construction and Time-Depth transformation, a precise directional model is constructed using the layer-by-layer approximation principle with reference to marker layers, improving the accuracy of the target spot and avoiding premature or delayed entry into the target;2) Based on a precise geological model, the dip angle of the strata ahead and the development of sweet spots are clearly defined, enabling optimized trajectory design for horizontal wells;3) Using “1 + N” dynamic modeling to update the geological model in real-time during the drilling process, and actively guide the drill bit through the horizontal segment smoothly by using multi-information judgment of the drill bit position. The actual drilling of 80 completed horizontal wells in this area show: That this approach effectively ensures the smooth trajectory and high-quality drilling rate of the horizontal well in the coal seam, providing a basis for subsequent hydraulic fracturing and increasing single-well production. At the same time, it has certain potential value and significance for similar coalbed methane developments under similar geological conditions.展开更多
LWD（logging while drilling） data has been used to explore complex subtle reservoirs by realtime visual interpretation and geo-steering.The method comprises of computer communication,well log data processing,formatio...LWD（logging while drilling） data has been used to explore complex subtle reservoirs by realtime visual interpretation and geo-steering.The method comprises of computer communication,well log data processing,formation recognition,reservoir modeling and model updating in real time.We studied the key technologies related to real-time LWD data visual interpretation and geo-steering and developed computer software with Chinese intellectual property rights covering the following important aspects： 1） real-time computer communication of well site LWD data;2） visualization of geological model and borehole information;3） real-time interpretation of LWD data;4） real-time geological model updating and geo-steering technology.We use field application examples to demonstrate the feasibility and validity of the proposed technologies.展开更多
In the process of shale gas drilling,geo-steering plays an important role in shale gas drilling.This paper analyzes the constituent elements of shale formation,and selects the most suitable constituent elements of sha...In the process of shale gas drilling,geo-steering plays an important role in shale gas drilling.This paper analyzes the constituent elements of shale formation,and selects the most suitable constituent elements of shale formation.A particle swarm optimization algorithm based on improved inertia weight and acceleration factor is proposed to optimize the parameters of support vector machine.The lithology identification model of shale formation is established based on IPSO-SVM.According to the experimental analysis based on the field historical data,the recognition rate of IPSO-SVM is increased by 17.79%,10.17%and 8.05%,respectively,compared with SVM,GA-PSO and PSO-SVM.In terms of running time,the running time of IPSO-SVM is 13.76s and 9.5s shorter than that of GA-PSO,PSO-SVM,respectively.By comparing the experimental results of different models,IPSO-SVM has the advantages of strong robustness,strong reliability,high accuracy and fast convergence speed.It provides a theoretical basis for precise geo-steering and finding the optimal shale layer.展开更多
文摘During the development phase horizontal wells are very efficient way to improve the production in the deep coal bed methane. The 8# coal seam in the XX block on the eastern edge of the Ordos Basin has challenges such as deep burial depth (>2000 m), thin coal sweet spot (3 m), and significant short-distance structural fluctuations. The challenges caused a high risk of missing targets and running out of the target layers, as well as difficulties in cementing and completion due to uneven well trajectories. To address these challenges, this paper focuses on solving the issues through detailed precise geological modeling, optimized trajectory design, and accurate seismic geology Steerable Drilling. 1) Based on reasonable velocity field construction and Time-Depth transformation, a precise directional model is constructed using the layer-by-layer approximation principle with reference to marker layers, improving the accuracy of the target spot and avoiding premature or delayed entry into the target;2) Based on a precise geological model, the dip angle of the strata ahead and the development of sweet spots are clearly defined, enabling optimized trajectory design for horizontal wells;3) Using “1 + N” dynamic modeling to update the geological model in real-time during the drilling process, and actively guide the drill bit through the horizontal segment smoothly by using multi-information judgment of the drill bit position. The actual drilling of 80 completed horizontal wells in this area show: That this approach effectively ensures the smooth trajectory and high-quality drilling rate of the horizontal well in the coal seam, providing a basis for subsequent hydraulic fracturing and increasing single-well production. At the same time, it has certain potential value and significance for similar coalbed methane developments under similar geological conditions.
基金funded by several Co. of CNPC and SINOPECChina National Science and Technology Major Projects of Oil & Gas (2011ZX05009-003)"863" Projects (2006AA060105)
文摘LWD（logging while drilling） data has been used to explore complex subtle reservoirs by realtime visual interpretation and geo-steering.The method comprises of computer communication,well log data processing,formation recognition,reservoir modeling and model updating in real time.We studied the key technologies related to real-time LWD data visual interpretation and geo-steering and developed computer software with Chinese intellectual property rights covering the following important aspects： 1） real-time computer communication of well site LWD data;2） visualization of geological model and borehole information;3） real-time interpretation of LWD data;4） real-time geological model updating and geo-steering technology.We use field application examples to demonstrate the feasibility and validity of the proposed technologies.
文摘In the process of shale gas drilling,geo-steering plays an important role in shale gas drilling.This paper analyzes the constituent elements of shale formation,and selects the most suitable constituent elements of shale formation.A particle swarm optimization algorithm based on improved inertia weight and acceleration factor is proposed to optimize the parameters of support vector machine.The lithology identification model of shale formation is established based on IPSO-SVM.According to the experimental analysis based on the field historical data,the recognition rate of IPSO-SVM is increased by 17.79%,10.17%and 8.05%,respectively,compared with SVM,GA-PSO and PSO-SVM.In terms of running time,the running time of IPSO-SVM is 13.76s and 9.5s shorter than that of GA-PSO,PSO-SVM,respectively.By comparing the experimental results of different models,IPSO-SVM has the advantages of strong robustness,strong reliability,high accuracy and fast convergence speed.It provides a theoretical basis for precise geo-steering and finding the optimal shale layer.
