DD143170A1 - PROCESS FOR PREVENTING THE LOSS OF PARTICULARLY SOLDERED SANDSTONES - Google Patents

Abstract

The present invention relates to a method for preventing the sanding of loose or partially solidified sandstones, the opened up by a cased and cemented hole are, when removing the coating medium. In doing so, the Preparation of the hydrodynamic connection between the cased and cemented drilling and storage rock and erection a homogeneous sand filter between pipe run and storage rock in one operation. By means of an erosion perforation, in which Quartz sand of the same grain size and grain distribution, as he Erection of the sand filter is necessary, is used, the Pipe tour perforated. After the perforation is at closed annulus of quartz sand to build the filter ever compressed according to the desired volume in the reservoir rock. following the string of strings is put on and the next one Perforation level opened. When the connection to the storage rock made in this level, becomes the previous level aufgesandet. There is the possibility that by pressing the filter sand in the now open level also a sand filter can be built. This continuous process of perforation and the pressing of filter sand can be continued until the entire memory area of interest with a homogeneous filter is provided.

Description

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Method for preventing the separation of loose or partial

Removal of gases or liquids from loose or partially solidified sandstones results in sanding of these sandstones * In order to avoid this sanding, filters are drilled in the holes that have intersected these loose or solidified sandstones and were cased to the final depth.

The present invention describes a new method for introducing sand filters into these cased bores. The perforation of the pipe run and the introduction of the sand filter are carried out in one operation.

Often, oil and gas deposits are found in more or less solidified sandstones and mined or built in such sandstones underground storage * Despite piping, cementation and perforation, it comes with the removal of naturally occurring or subsequently fed liquid and gaseous hydrocarbons to the silting of the reservoir rock , d. H * to mobilize storage particles, their accumulation in the borehole near zone or even discharge from the well, destruction of the underground and surface equipment of the well are the consequences of this submission ·

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Several methods are known to reduce or completely prevent the sanding of more or less solidified sandstones. , One of the known methods is called Frac-pac. The Fracpac is used when the storage is horizontally cased and cemented. After perforation of the Endrohrtour over the ges'amten storage area, the support material is above ground mixed with a suitable carrier liquid (fresh water, salt water, alkalis, gels) and pressed by means of appropriate Purapeinheiten in the space between perforated Endrohrtour and storage horizon.

The disadvantage of said method is that in the vertically inhomogeneous formation of the storage rocks individual areas do not receive support material and can be stimulated in the subsequent promotion to the sanding with the aforementioned dangers.

Object of the invention

The aim of the invention is to find a method which overcomes the disadvantages of the previous ones. Technology, in particular, the non-uniform inclusion of the perforated areas excludes. It was found that the perforation of the Sndrohrtour and the introduction of the filter from Stütaraaterisl can be done in one operation. The process of introducing the filter pack between tailpipe and store should be controlled so that each perforation opening receives support material and the thickness of the support pack between tailpipe and store can be varied according to the properties of the store rock.

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Explanation of the essence of the invention

The invention had the object of finding a method that both the piping, cementation and perforation of a hole in an outgoing in the promotion memory as well as the introduction of a filter of quartz sand or gravel with the same thickness of the support pack to reduce or reduce the Absandens admits. These requirements, the proposed method of Erosionpac largely meet. For the preparation of the hydrodynamic connection between probe and storage, the known method of erosional perforation is used. In contrast to the standard technology of erosion perforation, the abrasive material added to the perforating liquid for days is silica sand of the grain size needed for the sand filter. After perforation of the tube and cement jacket by erosion perforation in one to three levels of quartz sand is pressed into the memory and forms there the desired sand filter. The thickness of the sand filter around the bore depends on the duration of the pressing operation into the reservoir and can therefore be varied. Since only a limited number of perforations are ever needed, it is possible to ensure a uniform formation of the oil filter around the hole.

embodiment

The cased and cemented hole is perforated by erosion perforation in a plane with 4 holes per level. The perforating liquid is fresh water, the abrasive material is quartz sand of the grain size needed for the sand filter.

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The king room will remain open during this work stage. After the perforation of the first level with an effective perforation time of 10 ... 15 minutes, the annulus is closed. The head pressure adjusting at the annulus indicates whether a hydrodynamic connection to the reservoir has been established. If this indication is positive, the concentration of quartz sand per m perforation liquid is increased and pressed into the memory.

After pressing the calculated volume of quartz sand into the first plane, the perforation strand is pulled to the next perforation plane. With the annular space still closed, the perforation of the second level occurs with a reduced addition of abrasive material to the perforating liquid. After opening the second perforation level with an effective perforation time of 10 ... 15 minutes, the sand filter in this perforation plane is built up with an increased concentration of quartz sand. The first perforation interval is sent.

These operations are carried out until the desired storage area is perforated and provided with a sand filter. Finally, the quartz sand deposited on the bottom of the borehole is rinsed to the final depth.

Claims (3)

~ 5 · - 212 6 6 7 Invention claims 1, A method for preventing the sanding of loose or partially solidified sandstones, which have been intersected by a cased and cemented bore, characterized in that the preparation of the hydrodynamic connection between the bore and reservoir rock and the establishment of a vertically and horizontally homogeneous sand filter between Endrohrtour and storage rock is done in one operation, in which the. Perforation of the Endrohrtour by erosion perforation using fresh water as a perforating liquid and quartz sand of the grain size and particle size distribution, which is required for the sand filter for retaining the outgoing storage particles, as an abrasive material and in which immediately after the erosion perforation of. Endertube tour in one or more planes, but preferably in a plane, is begun with the pressing of the quartz sand using fresh water as a carrier liquid, wherein the thickness of the Sandfiltdrs depending on the volume of the pressed Quarzsnndes ^ can be varied, and in the after pressing the desired volume of quartz sand in the area just treated the preparation of the hydrodynamic connection between the bore and storage rock and the establishment of a sand filter between Endrohrtour and reservoir rock in the next higher storage area is carried out, wherein the previously treated storage area is sent. 2, method according to item 1, characterized in that aaß as perforating liquid for the production of hydrodynamic 212667 Bond between the well and storage rock and as a carrier liquid for the establishment of the horizontal and vertical homogeneous filter of other liquids, such as salt water, brine and liquid hydrocarbons, which are compatible with both the memory content and with the reservoir rock, used v / earth. 3. The method according to item 1, characterized in that the required for the preparation of the hydrodynamic connection between the bore and storage rock perforating liquids and the carrier liquid required for pressing the Quarzssndes chemicals in solid, liquid or gaseous form are added to the compatibility of these fluids with the memory contents and the reservoir rock to improve the viability of these fluids for the silica sand and the traceability of these fluids from the reservoir rock.