scholarly journals The status of deep geothermal well drilling in Kakkonda, Japan.

1993 ◽  
Vol 58 (5) ◽  
pp. 353-362 ◽  
Author(s):  
Seiji Saito
2021 ◽  
Author(s):  
Junichi Sugiura ◽  
Ramon Lopez ◽  
Francisco Borjas ◽  
Steve Jones ◽  
John McLennan ◽  
...  

Abstract Geothermal energy is used in more than 20 countries worldwide and is a clean, reliable, and relatively available energy source. Nevertheless, to make geothermal energy available anywhere in the world, technical and economic challenges need to be addressed. Drilling especially is a technical challenge and comprises a significant part of the geothermal development cost. An enhanced geothermal system (EGS) is a commercially viable thermal reservoir where two wells are interconnected by some form of hydraulic stimulation. In a commercial setting, fluid is injected into this hot rock and passes between wells through a network of natural and induced fractures to transport heat to the surface system for electricity generation. To construct EGS wells, vertical and directional drilling is necessary with purpose-built drilling and steering equipment. This is an application where oil-and-gas drilling tools and techniques can be applied. A recent well, 16A(78)-32, drilled as part of the US Department of Energy's (DOE's) Utah Frontier Observatory for Research in Geothermal Energy (FORGE) program, highlights some of the technical challenges, which include drilling an accurate vertical section, a curve section, and a 5300-ft 65° tangent section in a hard granitic formation at temperatures up to 450°F (232°C). Extensive downhole temperature simulations were performed to select fit-for-purpose drilling equipment such as purely mechanical vertical drilling tools, instrumented steerable downhole motors, measurement-while-drilling (MWD) tools, and embedded high-frequency drilling dynamics recorders. Downhole and surface drilling dynamics data were used to fine- tune bit design and motor power section selection and continuously improve the durability of equipment, drilling efficiency, and footage drilled. Drilling optimization techniques used in oil and gas settings were successfully applied to this well, including analysis of data from drilling dynamics sensors embedded in the steerable motors and vertical drilling tools, surface surveillance of mechanical specific energy (MSE), and adopting a drilling parameter roadmap to improve drilling efficiency to minimize drilling dysfunctions and equipment damages. Through drilling optimization practices, the instrumented steerable motors with proper bit selections were able to drill more than 40 ft/hr on average, doubling the rate of penetration (ROP), footage, and run length experienced in previous granite wells. This paper presents a case study in which cutting-edge oil-and-gas drilling technologies were successfully applied to reduce the geothermal well drilling time by approximately half.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hongyan Li ◽  
Pengtao Wang ◽  
Bin Liu ◽  
Xianyu Zhang ◽  
Hai Huang ◽  
...  

When the typically utilized method for detecting the drilling conditions of high-temperature geothermal wells is applied, the detection takes a long time, the detection results are inconsistent with the actual conditions, and there are problems such as low detection efficiency and large detection deviation. Therefore, a method for detecting the drilling conditions of high-temperature geothermal wells described by a unit quaternion is proposed. Based on quaternion theory, the quaternion model of the position and attitude is constructed to obtain the drilling attitude. According to the analysis results and the basic principle of kernel principal component analysis, a model is built to realize the detection of high-temperature geothermal well drilling conditions. The experimental results show that in many iterations, the time required is stable and lower than that of other comparison methods, and the detection errors are all lower than 10%. The proposed method has high detection efficiency and low detection errors.


2020 ◽  
pp. 26-29
Author(s):  
T.Sh. Salavatov ◽  
◽  
Y.I. Safarov ◽  
S.A. Musayeva ◽  
◽  
...  

The paper makes an effort to specify the relaxation time of subsurface rocks composing the borehole wall during geothermal well drilling justifying theoretical and practical researches. To solve mentioned issues, a theory of dumping of pressure fluctuations in non-stationary motion of drilling mud in the circulation system of well, based on the data of change of pressure and time consumption is applied and as a result a calculation formula obtained. The method has been tested in the well No 245 in Muradkhanly area.


Author(s):  
Raka Aditya Pratama ◽  
Astra Agus Pramana ◽  
Bambang Kustono

<em>Aiming for productive fault in Suban Agung Rim, Field X Cluster Y Bengkulu Province, Indonesia, PT Pertamina Geothermal Energy (PGE) drilled some wells to discover the potential awaited. However there are challenge awaits each meter ahead especially in reservoir sections where loss circulation is expected. Knowing the risk, PGE decided to drill the well utilizing aerated drilling. The method has known for decades to be the most effective approach in dealing loss circulation. The method applies certain value of compressed air to be injected in fluid stream, so bubbling process can be achieved in order to reduce the mud weight. The method has benefit to maintain ROP and minimize the risk for pipe get stuck due to poor hole cleaning in fractured formation. There are three wells drilled in Field X Cluster Y which has the same problem in 9-7/8” section; all experienced stuck pipe while drilling. During the process aerated drilling was utilized, however it was not sufficient. This paper will discuss and explain on how the occurrence happened and what to do next in similar condition to avoid the problems.</em>


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