oil-core-method-17.html
DTU Olie og Gas
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new and promising method increases the sweep area in existing
wells
dhrtc sheds light on the potential of using the radial jet
drilling
method to boost
oil
recovery from the existing horizontal
wells
in the north sea. ?e
oil
-bearing chalk strata in the north sea are highly porous. ?is means there are a lot of cavities with space for
oil
. nevertheless, the chalk is characterized by low permeability, so it is not easy for liquids such as water and
oil
to move. commonly, the chalk reservoirs are flooded by water to pro- duce more
oil
. under such recovery method, the fluids move through a relatively limited area around the in- jection and production
wells
. ?e
oil
industry has successfully developed a technology whereby the
wells
cover as large an area as possi- ble. ?is is achieved by
drilling
hori- zontall
wells
along the chalk strata, which are then stimulated with frac- tures or acid to improve
wells
? injec- tivity and productivity. even using such smart methods, may result in unswept
oil
-bearing areas - an unex- ploited potential for recovering more
oil
- in the reservoirs. a known drill- ing technology can bring these areas within reach; radial jet
drilling
(see graphic). dhrtc is working to adapt the method to the conditions in the north sea, particularly focusing on the deep part of the tor formation. ?e work involves everything from research in
drilling
technology and the development of numerical mod- els to developing the actual technolo- gy in cooperation with industry. ?radial jet
drilling
is a relatively mature technology in the
oil
industry, which has been applied in vertical and inclined
wells
. so far, it has not been used in the north sea?s horizontal
wells
,? says senior researcher hamid nick at dhrct. the research team postdoc saeed salimzadeh from dhrct is part of the research team developing computer models that sim- ulate radial jet
drilling
in the north sea?s chalk strata. ?e purpose is to enable the
oil
industry to plan profita- ble, new branching of existing
wells
in the north sea. ?e numerical models will be used, for example, to calculate possible improvements of the injec- tion processes and productivity, and indicate the expected ?durability? of the laterals which are drilled from the horizontal
wells
using jets of water. in some situations, the new bores may collapse and become blocked. ?us, laboratory tests of the method are conducted to evaluate the stabil- ity of the laterals in chalk. ?e tests are performed by phd student maiya medetbekova and supervised by helle foged christensen. helle is laboratory manager at geo, a firm of consulting engineers with subsurface expertise. ?e research group is also part of a large european horizon 2020 pro- ject with 10 partners, sure (novel productivity enhancement concept for a sustainable utilization of a ge- othermal resource). in the sure project, universities and industry are working together to learn more about radial jet
drilling
for improving energy mining. 18 dhrtc 2016 demo model awf2 improved
oil
recovery in the deeper part of the tor formation the demo model seeks to identify possi- bilities for increasing the recovery of
oil
in the deeper part of the tor formation in the halfdan field. logging of observation and monitoring
wells
along with 4d seismic recordings have shown an uneven verti- cal sweep mainly efficient in the upper parts. to improve the sweep efficiency in the lower part of the reservoir, research is being conducted into radial jet
drilling
technology for establishing smaller radial wellbores from the existing horizontal
wells
. the research focuses on modelling of radial wellbores and induced fractures as well as on the downhole tools needed to operate in the long horizontal section of the existing
wells
. dhrtc?s hypothesis recovery of hydrocarbons from the tor formation can be increased by providing access to the deeper sections from the ex- isting
wells
and improve the vertical sweep efficiency. this can be achieved using ra- dial jet
drilling
or alternative methods that may further be combined with methods for enhancing the induced fractures in the formation. dhrtc research to achieve the objective of improving recovery in the deeper part of the tor for- mation, dhrtc is conducting research into, for example: ? modelling of stability and efficiency of jetted wellbores ? modelling and simulation of induced fractures ? laboratory testing of the effect on mechanical properties from jetting ? preliminary study on development of composite c
oil
ed tubing ? simulations for assessing financial viability of solution
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