Study On Design Of Hydraulic Pumping Unit On Offshore Platform

At present,the reserves of heavy oil in China's bohai bay region are abundant,and it accounted for 85% of the total oil reserves have been found.Bohai bay region has become the key area of offshore heavy oil development.Offshore heavy oil exploitation mainly used the method of cyclic steam stimulation.Due to the putting forward and down of electric submersible pump and other mining equipment,affecting the spread of bottom hole temperature and temperature field,and reducing the efficiency of thermal recovery.To solve this problem,this paper drew lessons from widely used and mature on land thermal heavy oil recovery technology of “steam huff and puff along with the combination of pumping unit,oil-well pump and sucker rod in artificial lifting”,designed a kind of hydraulic pumping unit can be used in offshore platform,solving the problem of submersible electric pump is not suitable for offshore heavy oil development,achieving the goal of offshore oil sucker rod.1.The design requirements of hydraulic pumping unit on offshore platformBased on the technological requirements of heavy oil exploitation at present and the well working conditions of target platform,we have investigated the existing hydraulic pumping unit,analyzed the pumping unit suspension point load characteristic and the polished rod motion characteristics,determined the maximum load of the upper and lower stroke,maximum speed and maximum polished rod acceleration and other parameters.At the same time,we have analyzed oil production space situation of the target offshore,determined the size of the designed hydraulic pumping unit on offshore platform requirements,laid a foundation for the design of the pumping unit.2.The design of hydraulic pumping unit on offshore platformCombining with the design requirements for pumping unit,we have designed and optimized the overall scheme of hydraulic pumping unit on offshore platform,determined the optimal solution,elaborated the composition and working principle of three parts: mechanical system,hydraulic system and the control system.According to the function different,we divided the pumping unit into four parts: drive power system,mechanical drive system,execution system and auxiliary system,and designed respectively the detailed of them.3.The finite element analysis of hydraulic pumping unit frame on offshore platformBased on ANSYS software,finite element model of the pumping unit frame has been established.We have taken the static analysis and modal analysis under the condition of different ground and wind load.Through the analysis of the frame under the condition of different ground,we have put forward a new design idea for pumping unit frame.Through the analysis of the frame under the condition of different wind load,we have provided the basis for the installation of the pumping unit.4.The impact analysis of hydraulic pumping unit and offshore platformThe finite element analysis of LD27-2 WHPB wellhead platform was established by applying the ANSYS software.We have analyzed the influence of whole and local situation of LD27-2 WHPB wellhead platform load under the situation before and after the pumping unit in the worst case.Through analysis and calculation,we have got the installation of the pumping unit will have little impact on the platform of main leg.We have determined the optimal size of target platform middle wellhead deck beam,put forward a redesign thought of offshore platform,laid a foundation for the realization of offshore oil recovery with rod pumping.