Abstract: The present invention describes a vertical cylindrical exchanger-reactor for carrying out endothermic reactions, comprising a shell enclosing a plurality of tubes inside which the reactive fluid moves, said tubes being of the bayonet type, and the heat transfer fluid, in this case hot gases, being channeled inside chimneys surrounding said bayonet tubes. The bayonet tubes and the chimneys are suspended from the upper dome of the reactor. This reactor may operate with a pressure difference between the tube side and the shell of up to 100 bars. The hot gases are admitted into the reactor at temperatures of up to 1300° C.

Abstract: The present invention describes a vertical cylindrical exchanger-reactor for carrying out endothermic reactions, comprising a shell enclosing a plurality of tubes inside which the reactive fluid moves, said tubes being of the bayonet type, and the heat transfer fluid, in this case hot gases, being channelled inside chimneys surrounding said bayonet tubes. The bayonet tubes and the chimneys are suspended from the upper dome of the reactor. This reactor may operate with a pressure difference between the tube side and the shell of up to 100 bars. The hot gases are admitted into the reactor at temperatures of up to 1300° C.

Abstract: The invention relates to an optimized method for producing a hot gas by oxidation of an active material having an oxidized form and a reduced form using a rotary reactor or a simulated-rotation reactor. According to the invention, the production cycle comprises a flow interruption between an oxidation stage and a scavenging stage.

Abstract: A method of managing the valves of a simulated moving bed separation system comprising at least one column of adsorbent beds split into several zones delimited by injection and draw-off points, allowing finer monitoring of a determined concentration profile. The method comprises, during each period between the shift times of the injection and draw-off points, in opening and closing a first valve located at one end of a zone according to a determined law, while opening and closing the valve downstream from the first valve in relation to the direction of flow of the recirculation flow, according to the same law with a lag, referred to as overlap time, in relation to the first valve, which is less than or equal to the period, the law imposing a constant total flow rate for the flow passing through the two consecutive valves throughout the overlap time.

Abstract: A method of managing the valves of a simulated moving bed separation system comprising at least one column of adsorbent beds split into several zones delimited by injection and draw-off points, allowing finer monitoring of a determined concentration profile. The method comprises, during each period between the shift times of the injection and draw-off points, in opening and closing a first valve located at one end of a zone according to a determined law, while opening and closing the valve downstream from the first valve in relation to the direction of flow of the recirculation flow, according to the same law with a lag, referred to as overlap time, in relation to the first valve, which is less than or equal to the period, the law imposing a constant total flow rate for the flow passing through the two consecutive valves throughout the overlap time.

Abstract: For co-production of metaxylene and paraxylene from a hydrocarbon feedstock in a simulated moving bed in a chromatographic column (1) that contains a number of beds 1, 2,3, 4 . . . of an adsorbent, interconnected in a loop, the column comprises an injection of the feedstock, a draw-off (14) of a first raffinate, a draw-off (17) of a second raffinate that comprises metaxylene, an injection of desorbent and a draw-off of an extract that delivers paraxylene. The injection positions and the draw-off position of the extract are offset periodically by one bed in the direction of flow of the main flux that circulates in the column. First raffinate (14) that comprises desorbent, orthoxylene, metaxylene and ethylbenzene is drawn off continuously or intermittently, and second raffinate (17) R2 that comprises orthoxylene and metaxylene is drawn off intermittently. The second raffinate is distilled in such a way as to recover orthoxylene and metaxylene separately with at least 99% purity and with an improved yield.

Abstract: A process for determining by simulation the optimum stabilization conditions of a simulated moving bed (SMB) separation system allows to obtain set values for the purity of an extracted constituent and for the efficiency. In order to determine the optimum flow rates, a single simulation is carried out, which includes a succession of stages intended for rectification of the fluid flow rates during limited time intervals (T), including each, after each time interval, comparison of the respective purity degrees and efficiencies obtained, resulting from situations stemming from simulations over a time interval (&Dgr;t) where rectifications are applied to at least one flow rate, with those of a reference situation resulting from a simulation over the same time interval but without flow rate rectification, followed by a selection of flow rates aimed to minimize the quantity of impurities in the extract and the quantity of constituent in the raffinate.

Abstract: For co-production of metaxylene and paraxylene from a hydrocarbon feedstock in a simulated moving bed in a chromatographic column (1) that contains a number of beds 1, 2, 3, 4 . . . of an adsorbent, interconnected in a loop, the column comprises an injection of the feedstock, a draw-off (14) of a first raffinate, a draw-off (17) of a second raffinate that comprises metaxylene, an injection of desorbent and a draw-off of an extract that delivers paraxylene. The injection positions and the draw-off position of the extract are offset periodically by one bed in the direction of flow of the main flux that circulates in the column. First raffinate (14) that comprises desorbent, orthoxylene, metaxylene and ethylbenzene is drawn off continuously or intermittently, and second raffinate (17) R2 that comprises orthoxylene and metaxylene is drawn off intermittently.

Abstract: The device comprises at least one column 1 that is filled with a number of beds A.sub.n having an adsorbent that are separated by a fluid distributor plate P.sub.1. Each plate is divided into a number of sectors P.sub.10 and P.sub.11, and each sector comprises at least one fluid distribution chamber 13 that is pierced with openings and a circulation space 8 in the vicinity of the openings. The chambers of the plate are connected to a line 10 for transfer to the outside. With respect to the chambers on a plate, transfer line 10 P, is connected to another transfer line 20 relative to chambers 23 on another plate (P.sub.i+1 or P.sub.i+2) that is arranged downstream by a bypass line L.sub.1,2. The latter comprises means 14, 15, 16 for monitoring and adjustment of the flow of fluid that circulates there, such that the distribution chambers are flushed by a fluid which has approximately the same composition as that of the fluid that circulates through circulation space 8 at each of the chambers.

Abstract: The device comprises at least one column 1 that is filled with a number of beds A.sub.n having an adsorbent that are separated by a fluid distributor plate P.sub.i. Each plate is divided into a number of sectors P.sub.10 and P.sub.11, and each sector comprises at least one fluid distribution chamber 13 that is pierced with openings and a circulation space 8 in the vicinity of the openings. The chambers of the plate are connected to a line 10 for transfer to the outside. With respect to the chambers on a plate, transfer line 10 P.sub.i is connected to another transfer line 20 relative to chambers 23 on another plate (P.sub.i+1 or P.sub.i+2) that is arranged downstream by a bypass line L.sub.1,2. The latter comprises means 14, 15, 16 for monitoring and adjustment of the flow of fluid that circulates there, such that the distribution chambers are flushed by a fluid which has approximately the same composition as that of the fluid that circulates through circulation space 8 at each of the chambers.

Abstract: The invention is a method for modeling the effects of interactions between wells on the watercuts in effluents produced by one or more wells through a zone of an underground hydrocarbon reservoir under development, swept by a fluid under pressure injected through one or more injection wells or swept by water from an aquiferous zone, in order to optimize the reservoir production. The method includes selecting a set of significant data from measurements taken from sweep fluid injection records and from records relative to the effluents produced by a series of wells of the zone, and setting up, by means of iterations, an optimized linear model connecting the variations with time of these watercuts with the variations with time of the significant data. The invention is useful to optimize the petroleum production of a reservoir.

Abstract: The present invention relates to a system and to a method designed to estimate the effective displacement of a drill bit fastened to the end of a drill string and driven into rotation in a well by surface driving means. A non-linear physical model of the drilling process based on general mechanics equations is used in the invention. The following stages are performed in the method:the parameters of said model are identified by talking account of the parameters of said well and of said string,said model is linearized about a working point,said linearized model is reduced while keeping only some of the specific modes of the state matrix of said model,the displacement of the drill bit is computed in real time by means of the reduced model and of at least one parameter measured at the surface.FIG. 4 to be published.

Abstract: In a method and to a system suited for monitoring the behaviour of a drill bit (2), the damping associated with a natural mode of the torsional oscillations measured by at least one measuring device (4) placed in the drill string is determined. The appearance of a stick-slip type dysfunctioning is predicted when the damping value decreases significantly as a function of time, and drilling parameters are then varied in order to avoid the appearance of the dysfunctioning.

Abstract: The present invention relates to a method and to a system for transmitting a signal associated with drilling conditions and/or the behavior of a drill string element. The present invention comprises stages of segmentation of the signal, and of decomposition of each segment into a wavelet so as to obtain the wavelet coefficients. The method also comprises the stage of transmission of certain characteristic coefficients. The present invention also relates to a system suited for implementing the method.

Abstract: The present invention relates to a method and to a system for analyzing drilling conditions and/or the behaviour of a drill string element. It comprises the stages as follows:acquisition of a signal,calculation means are operated, which determine the wavelet coefficients of segments of the signal, the segments are merged to form a homogeneous segment,a magnitude associated with each homogeneous segment is determined.The invention further relates to a system for implementing the method.

Abstract: A method and a system suited for controlling the behavior of a drill bit includes an additional resistant torque added to the torque about the drill bit so that the overall torque about the drill bit is an increasing function of the rotary speed of the bit. The system includes control means suited for creating an additional resistant torque about the bit.