Tamyr techology of microhole drilling from horizontal wellbores using whipstock for draining and formation stimulation

UDK: 622.243.24 + 622.248.67

DOI: 10.24887/0028-2448-2020-7-50-52

Key words: drilling of lateral drainholes, horizontal wellbore, whipstock, open hole, drainage, acidizing, productive formation

Authors: I.Kh. Makhmutov (TatNIPIneft, RF, Bugulma), R.Z. Ziyatdinov (TatNIPIneft, RF, Bugulma), R.I. Nasryev (TatNIPIneft, RF, Bugulma), R.N. Sadykov (Oil and Gas Production Department Leninogorskneft, RF, Leninigorsk)

This paper presents a drilling/formation stimulation technology Tamyr, enabling to drill multiple microholes that diverge fr om a main horizontal open hole like roots of a tree. The initial horizontal well might be a newly drilled completion or a well under production. The diameter of the micro drainholes is 68 mm, the length is up to 100 m. For oriented sidetracking, a whipstock for open holes is used. To increase its wear resistance, the working surface of the whipstock is nitrogenized to achieve the Vickers hardness number HV 600-650. The coiled tubing-conveyed BHA includes a bottomhole motor with a mill-tooth bit. Following each sidetracking, hydrochloric acidizing of the bottomhole zone is performed: CT-conveyed jet nozzle is run to bottom, then pulled to the point of exit from the main horizontal wellbore with simultaneous injection of hydrochloric acid. Tamyr technology is particularly suited for layered reservoirs with gas-/oil-water contact, wh ere fracture stimulation treatments to enhance production cannot be performed, and for reservoirs with poor porosity and permeability, that is, reservoirs that have been earlier considered marginal. Multiple drainholes maximize reservoir contact and increase wellbore drainage area producing from the isolated reservoir compartments and pockets of bypassed oil not penetrating into the adjacent gas- or water-saturated intervals. Micro drainholes are able to enhance production better than a single-bore horizontal well, being more economical and beneficial at that. Benefits and advantages include less total rig time, fewer materials required for drilling and completion, decreased volumes of drilling fluid and drilling cuttings resulting in reduced disposal costs and less risk of drilling mud invasion. Overall environmental impact is considerably reduced. The technology improves drainage control with much less number of wells and decreased scope of drilling. References 1. URL: https://www.norwegianamerican.com/fishbones-sucks-the-marrow-from-wells/ 2. Patent RU 2684557 C1, Well horizontal shaft drainage zone expansion method by the distant sections acid treatment with the side channels development, Inventors: Ismagilov F.Z., Tabashnikov R.A., Akhmetshin R.M., Ziyatdinov R.Z. 3. Patent RU 2696696 C1, Deflecting device for drilling of branches from horizontal borehole, Inventor: Ziyatdinov R.Z. 4. Patent RU 2709262 C1, Method of drilling and development of offshoot from horizontal well, Inventors: Makhmutov I.Kh., Ziyatdinov R.Z.