Study of the Hole Wall Soil's Capacity by the Action of the Bearing Device of Rodless Drilling Rig

In order to ensure the bearing device of rodless drilling rig to press stably against the hole wall, it has to analyze the contact between the soil pore wall and the bearing device to study whether the soil pore will shear failure. This paper uses the method to calculate the additional stress of any point in soil mechanics to get the three-dimensional stress state of any point of the soil pore under the support plate, and use the numerical analysis method to calculate the shear stress and its relative intensity. Under the circumstances of maximum torque and maximum pressure, ABAQUS is used to make a finite element analysis of the capacity of the soil pore. The results of numerical analysis and FEA indicate that in the condition of the support plate will not deform; the contact area between the soil pore and the support plate is rectangular; in the force process, the soil under the ends of the support plate have the trend of yield, while it meets the condition of Mohr-Coulomb not to yield generally.

Upgrading, Transforming, and Standardizing of Offshore Oil Drilling Equipment in China

This paper discusses the development of China's oil exploration & drilling equipment, and it focuses mainly on the domestication, industrialization, and standardization of fixed offshore drilling rigs primarily constructed by CNOOC. Considering the manufacturing of and application of deepwater drilling equipment in China, the authors put forward suggestions regarding industry policies and the standardization of China's offshore engineering equipment.

Inverse kinematics of a heavy duty manipulator with 6-DOF based on dual quaternion

An iterative method is introduced successfully to solve the inverse kinematics of a 6-DOF manipulator of a tunnel drilling rig based on dual quaternion, which is difficult to get the solution by Denavit-Hartenberg(D-H) based methods. By the intuitive expression of dual quaternion to the orientation of rigid body, the coordinate frames assigned to each joint are established all in the same orientation, which does not need to use the D-H procedure. The compact and simple form of kinematic equations, consisting of position equations and orientation equations, is also the consequence of dual quaternion calculations. The iterative process is basically of two steps which are related to solving the position equations and orientation equations correspondingly. First, assume an initial value of the iterative variable; then, the position equations can be solved because of the reduced number of unknown variables in the position equations and the orientation equations can be solved by applying the solution from the position equations, which obtains an updated value for the iterative variable; finally, repeat the procedure by using the updated iterative variable to the position equations till the prescribed accuracy is obtained. The method proposed has a clear geometric meaning, and the algorithm is simple and direct. Simulation for 100 poses of the end frame shows that the average running time of inverse kinematics calculation for each demanded pose of end-effector is 7.2 ms on an ordinary laptop, which is good enough for practical use. The iteration counts 2-4 cycles generally, which is a quick convergence. The method proposed here has been successfully used in the project of automating a hydraulic rig.

Selecting Optimal Drill Rigs by Grey Relational Analysis Method

Based upon the main properties of the relational analysis in grey system theory, a new method to select optimal drill rigs is proposed in this paper. Under the unified technique economic index, with the practical data of four kinds of drill rigs in the mining district, east of Sichuan, China, an optimal reference number series was constructed. Through calculating the relational grade between the technique economic indices of various drill rigs and the reference number series and making a relational sequence in accordance with priority, the results achieved are in conformity with that of reference by Fuzzy Set Theory, and grey situation decision making and yet this method is simple, easy and intuitive in analysis etc..

Environmental Risk Assessment for Exploration and Extraction Processes of Unconventional Hydrocarbon Deposits of Shale Gas and Tight Gas:Pomeranian and Carpathian Region Case Study as Largest Onshore Oilfields

Shale gas and tight gas exploration and extraction processes create potential threats to the environment.In Poland,no comprehensive guidelines for environmental risk assessment have been prepared so far.This paper presents a proposal of environmental risk assessment methodology which can be used for corporate risk management procedures during exploration and extraction of unconventional hydrocarbons in Poland.The most frequent environmental threats that may occur during the exploration and exploitation of unconventional hydrocarbon deposits include degradation of soils through construction of drilling rigs and access roads,landforms change,local soil pollution caused by fuels,cleaning agents and materials used to prepare drilling fluids,rubble,cement,gravel,pollution of surface and underground water as a result of emergency discharges of sewage,infiltration of pollution from waste reservoirs,disturbance of hydrogeological equilibrium through significant water intake,noise and atmospheric pollution resulting from the combustion of fuels.To check the level of these threats' six exploration sites form Pomeranian and Carpathian region of Poland(3 wells of shale gas and 3 wells of tight gas) have been evaluated in detail,and the risk quantification has been made.Because of a local,short-term and reversible environment impact,the environmental risks for the exploration and extraction processes of unconventional hydrocarbons have been found to be medium or negligibly small.It is recommended that using the same methodology for other regions of Poland where we can find unconventional hydrocarbons and it can be enriched in dedicated application with spatial maps to give the investors a quick feedback on the potential environmental risks.