Deep Geothermal Well Construction Problems and Possible Solutions

2021 ◽  
Author(s):  
Mikhail Yakovlevich Gelfgat ◽  
Aleksandr Sergeevich Geraskin
Keyword(s):  
High Pressure ◽  
Geothermal Energy ◽  
Oil And Gas ◽  
Directional Drilling ◽  
Geothermal Well ◽  
Coiled Tubing ◽  
Deep Wells ◽  
Fluid Jets ◽  
Drilling Technology ◽  
Geothermal Wells

Abstract The geothermal energy is one of the most promising sources of electricity on the planet; it is available almost anywhere on the continents and resources are inexhaustible. The realization of these possibilities requires solving the problems of deep wells (6-10 km) construction, when the lower horizons are practically impermeable crystalline basement rocks. For effective use of the Earth's heat, bottomhole temperatures must be within 200-300°C. World experience of such deep wells construction is very limited, some examples are given in this work. Known schemes of geothermal energy application requires at least two wells construction - for cold fluid injection and superheated fluid production. The rock - circulating fluid heat exchange in the bottomhole requires drilling of inclined, horizontal, or multi-lateral boreholes and hydraulic fracturing application. Such technologies are widely used in the oil and gas fields, but not in crystalline rocks. The article presents an analysis of the prospects for the geothermal wells construction efficiency increasing by using modern directional drilling systems, drilling with casing, technologies for complications eliminating. The possibilities of using alternative hard rock drilling methods by enhancing the standard formation destruction with drill bits are discussed. These are hydraulic hammers, high-pressure abrasive and fluid jets, laser drilling. A fundamentally new plasma drilling technology is considered. The most serious limitation of alternative drilling prospects is the need of additional "supply lines" to the bottom: high-pressure fluid; electricity; a plasma forming agent, etc. In this regard, options are being considered for the development of continuous drill strings such as coiled tubing, umbilical, flexible composite systems like subsea pipelines. Some of technological solutions for deep geothermal wells construction, and implementation of petrothermal energy schemes for potential projects are proposed. The paper provides an idea of the geothermal well construction technologies, which can ensure the implementation of advanced geo-energy schemes. The problems of geothermal engineering and possible solutions to overcome them, which will contribute to the development of geothermal energy, as the most effective option for decarbonization, are indicated.

Oil and Gas Drilling Optimization Technologies Applied Successfully to Unconventional Geothermal Well Drilling

2021 ◽  
Author(s):  
Junichi Sugiura ◽  
Ramon Lopez ◽  
Francisco Borjas ◽  
Steve Jones ◽  
John McLennan ◽  
...  
Keyword(s):  
Geothermal Energy ◽  
Oil And Gas ◽  
Optimization Techniques ◽  
Geothermal System ◽  
Well Drilling ◽  
Geothermal Well ◽  
Gas Drilling ◽  
Drilling Tools ◽  
Drilling Optimization ◽  
Oil And Gas Drilling

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.

Obtaining Zonal Isolation in Geothermal Wells

2021 ◽  
Author(s):  
Allam Putra Rachimillah ◽  
Cinto Azwar ◽  
Ambuj Johri ◽  
Ahmed Osman ◽  
Eric Tanoto
Keyword(s):  
Best Practices ◽  
Oil And Gas ◽  
Lessons Learned ◽  
Free Fluid ◽  
High Heating Rate ◽  
Lost Circulation ◽  
Geothermal Well ◽  
Geothermal Wells ◽  
Zonal Isolation ◽  
Primary Cementing

Abstract Cementing is one of the sequences in the drilling operations to isolate different geological zones and provide integrity for the life of the well. As compared with oil and gas wells, geothermal wells have unique challenges for cementing operations. Robust cementing design and appropriate best practices during the cementing operations are needed to achieve cementing objectives in geothermal wells. Primary cementing in geothermal wells generally relies on a few conventional methods: long string, liner-tieback, and two-stage methods. Each has challenges for primary cementing that will be analyzed, compared, and discussed in detail. Geothermal wells pose challenges of low fracture gradients and massive lost circulation due to numerous fractures, which often lead to a need for remedial cementing jobs such as squeeze cementing and lost circulation plugs. Special considerations for remedial cementing in geothermal wells are also discussed here. Primary cement design is critical to ensure long-term integrity of a geothermal well. The cement sheath must be able to withstand pressure and temperature cycles when steam is produced and resist corrosive reservoir fluids due to the presence of H2S and CO2. Any fluid trapped within the casing-casing annulus poses a risk of casing collapse due to expansion under high temperatures encountered during the production phase. With the high heating rate of the geothermal well, temperature prediction plays an important part in cement design. Free fluid sensitivity test and centralizer selection also play an important role in avoiding mud channeling as well as preventing the development of fluid pockets. Analysis and comparison of every method is described in detail to enable readers to choose the best approach. Massive lost circulation is very common in surface and intermediate sections of geothermal wells. On numerous occasions, treatment with conventional lost-circulation material (LCM) was unable to cure the losses, resulting in the placement of multiple cement plugs. An improved lost circulation plug design and execution method are introduced to control massive losses in a geothermal environment. In addition, the paper will present operational best practices and lessons learned from the authors’ experience with cementing in geothermal wells in Indonesia. Geothermal wells can be constructed in different ways by different operators. In light of this, an analysis of different cementing approaches has been conducted to ensure robust cement design and a fit-for-purpose cementing method. This paper will discuss the cementing design, equipment, recommendations, and best available practices for excellence in operational execution to achieve optimal long-life zonal isolation for a geothermal well.

Coiled tubing drilling for unconventional reservoirs: the importance of cuttings transport in directional drilling

2014 ◽  
Vol 54 (1) ◽  
pp. 329
Author(s):  
Mohammadreza Kamyab ◽  
Nelson Chin ◽  
Vamegh Rasouli ◽  
Soren Soe ◽  
Swapan Mandal
Keyword(s):  
Rheological Properties ◽  
Oil And Gas ◽  
Fluid Velocity ◽  
Oil And Gas Industry ◽  
Unconventional Reservoirs ◽  
Directional Drilling ◽  
Flow Loop ◽  
Cuttings Transport ◽  
Cleaning Efficiency ◽  
Coiled Tubing

Coiled tubing (CT) technology has long been used in the oil and gas industry for workover and stimulation applications; however, the application of this technology for drilling operations has also been used more recently. Faster tripping, less operational time, continuous and safer operation, and the requirement for fewer crew members are some of the advantages that make CT a good technique for drilling specially deviated wells, in particular, in unconventional reservoirs for the purpose of improved recovery. Cuttings transport in deviated and horizontal wells is one of the challenges in directional drilling as it is influenced by different parameters including fluid velocity, density and rheological properties, as well as hole deviation angle, annulus geometry and particle sizes. To understand the transportation of the cuttings in the annulus space, therefore, it is useful to perform physical simulations. In this study the effect of wellbore angle and fluid rheological properties were investigated physically using a flow loop that has been developed recently for this purpose. The minimum transportation velocity was measured at different angles and an analysis was performed to study the fluid carrying capacity and hole cleaning efficiency. The results indicated how the change in wellbore angle could change the cuttings transport efficiency.

Directional drilling oil and gas wells

2017 ◽  
Author(s):  
Вячеслав Нескоромных ◽  
Vyacheslav Neskoromnykh
Keyword(s):  
Oil And Gas ◽  
Directional Drilling ◽  
Gas Wells ◽  
Field Of Study ◽  
Business Training ◽  
Oil And Gas Wells ◽  
Drilling Technology

The basic issues of the theory and technique of directional drilling technology applied to drilling for oil and gas. Provides information on the causes and patterns of curvature of the wells, tools, and technologies for drilling wells along set trajectories, technologies and technical means of the curvature of the wells, the drilling of multilateral wells. Examples of calculations and the basic terminology. For students enrolled in field of study 21.03.01 "Oil and gas business", training 21.03.01.01 "Drilling oil and gas wells" (fgos VPO – 2015); specialty 21.05.06 "Oil and gas equipment and technologies", specialization "Technology of drilling oil and gas wells" (fgos VPO – 2014).

Geothermal Well Construction: A Step Change in Oil and Gas Technologies

2021 ◽  
Vol 73 (01) ◽  
pp. 32-35
Author(s):  
Judy Feder
Keyword(s):  
Chemical Composition ◽  
Geothermal Energy ◽  
Oil And Gas ◽  
Reservoir Characterization ◽  
Engineering Problem ◽  
University Of Texas ◽  
Geothermal Well ◽  
Well Design ◽  
Major Player ◽  
The Cost

Geothermal energy has been described as an engineering problem that, when solved, provides the clean, reliable, safe, and affordable energy being sought globally. It is highly likely that the engineers who play the biggest role in solving that problem, and the technologies they adapt and advance, will come from oil and gas. There is enough energy in the earth’s crust, just a few miles down, to power all of humanity for ages, according to the US Advanced Research Projects Agency-Energy. The problem is how to tap into it safely, efficiently, and cost effectively. After many years of failure to launch because of technology or cost limitations, new companies and technologies - and smarter ways of leveraging those that already exist - are bringing geothermal out of its doldrums, to the point that it may finally be ready to scale and become a major player in the transition to cleaner energy, according to Jamie Beard, executive director of the Geothermal Entrepreneurship Organization (GEO) at The University of Texas at Austin (UT-Austin). “The cutting-edge technological developments in geothermal are devoted to drilling into ever-deeper, hotter, and harder rock,” she said, “and oil and gas holds the key to cost reduction for all of these concepts.” Eric Van Oort, drilling and well engineering expert, educator, and scientist, agrees. The UT-Austin engineering professor and director of the rig automation and performance improvement in drilling (RAPID) industry consortium, said, “Fifty to seventy-five percent of the cost of geothermal development is tied up in drilling and well construction. To scale it, we have to reduce that cost.” Designing for Extremes Well design for geothermal wells is similar to that for oil and gas wells. The challenges arise from drilling deeper and deeper, into hotter and hotter rock. Heat ranging from 150°C (302°F) to 373°C (703°F) and above can be used to profitably generate electricity. Oil and gas well designs traditionally have not had to contend with these extremes. Thermal considerations are unavoidable in deep geothermal well construction. Temperature and thermal effects, chemical composition of produced fluids, and rate of production or pressure depletion pose significant challenges to well casing and design. Nick Cameron, reservoir characterization manager at BP and leader of the supermajor’s studies into geothermal energy, said his company is using corporate data, geological understanding, and oil and gas expertise and experience to look at where their technology can reduce risk and drive down the cost of development. “Metallurgical understanding of materials and how they handle heat is crucial to these efforts,” he said. “Fortunately, there have been significant advancements in this area in recent years.” Cameron said that much work is also being done into changing the chemical composition of the fluids that flow through the geothermal reservoirs.

Development of a high-frequency torsional impact generator for improving drilling efficiency

2013 ◽  
Vol 228 (11) ◽  
pp. 1968-1977 ◽  
Author(s):  
Xiaohua Zhu ◽  
Liping Tang
Keyword(s):  
High Frequency ◽  
Oil And Gas ◽  
Impact Frequency ◽  
Element Analysis ◽  
Stick Slip ◽  
Deep Wells ◽  
Experimental Apparatus ◽  
The Finite Element Analysis ◽  
Drilling Technology ◽  
The Impact

The drilling of deep wells has to face problems to suppress stick-slip vibrations, especially for tough formations. Such problems induce frequent tool failures and poor well quality. Torsional impact drilling is an emerging drilling technology for improving the productivity of oil and gas by mitigating the stick-slip vibration. In this paper, a high-frequency torsional impact generator has been developed in order to investigate this drilling technology. Mechanism of torsional impact as a means of stick-slip mitigation is studied. Structure and operating principle of the tool have been presented. The finite element analysis approach is utilized in the analysis of applicability of the impact unit which is most significant for the tool. The analysis indicates that the impact unit operates successfully. An experimental apparatus is developed to examine the applicability of the proposed numerical method to the analysis of the impact unit. Laboratory tests with different impact frequency are conducted with the apparatus. It is verified that the impact system operates regularly, and high-frequency torsional impacts are generated. In addition, impact parameters of the apparatus which will be helpful to the study of the high-frequency torsional impact drilling are obtained.

scholarly journals НАУКОВІ ТЕНДЕНЦІЇ БУРІННЯ ГЛИБОКИХ НАФТОГАЗОВИХ СВЕРДЛОВИН

2019 ◽  
Vol 1 (1(31)) ◽  
pp. 18-21
Author(s):  
Мирослава Чернова
Keyword(s):  
High Pressure ◽  
Corrosion Fatigue ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Well Drilling ◽  
Gas Industry ◽  
Deep Well ◽  
Deep Wells ◽  
Deformed State ◽  
Drill Column

The essential problems in oil and gas industry are corrosion-fatigue breakage of drill column elements, sticking of drilling and heavy-weight drill pipes, taking place in drilling of directional and horizontal wells. The stickings are caused by friction, emerging between sides of hole and elements of drilling column. The frictions block assurance of core integrity in core receive. The failure resistance by using polymer and composite materials for surface treatment under influence of triboprocess and corrosion-fatigue breakage is considered in the article.The problem of deep well drilling is considered, which is connected with the prevention of the seizure phenomenon between the walls of the drill column and the barrel of deep wells. The design of the coupling connection of casing pipes with a high pressure sealing element is provided to provide the tightness of the casing columns at high pressure and temperature parameters. The elastically deformed state of the pipes with the inserted sealing element is scientifically substantiated.

Successful Implementation of the PMCD Technology for Drilling and Completing the Well in Incompatible Conditions at Severo – Danilovskoe Oil & Gas Field

2021 ◽  
Author(s):  
Dmitry Krivolapov ◽  
Ivan Masalida ◽  
Artem Polyarush ◽  
Vyacheslav Visloguzov ◽  
Alexey Averkin ◽  
...  
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Back Pressure ◽  
Successful Implementation ◽  
Drilling Mud ◽  
Gas Field ◽  
Lost Circulation ◽  
Well Completion ◽  
Drilling Technology ◽  
Operating Window

Abstract This paper discusses the successful implementation of PMCD (Pressurized Mud Cap Drilling) technology at Severo – Danilovskoe oil and gas field (SDO) located in the Irkutsk region. The abnormally high-pressure reservoir B1 and the abnormally low-pressure reservoir B5 are the target layers in this field. Wells drilling at SDO is accompanied with simultaneous mud losses and inflows conditions, especially if the strata B1 is being penetrated. Pumping lost circulation materials (LCM) and cement plugs do not solve lost circulation complications which subsequently lead to oil and gas inflows. As a result, most of such wells are getting abandoned. It was assumed that complications in this formation occurs due to the narrow safe pressures’ operating window (ECD window), therefore, the managed pressure drilling technology (MPD) was initially used as a solution to this problem. However, after the penetration of the abnormally high formation pressure B1 horizon with a pore pressure gradient of 1.86 g/cm3 it was found that there is no operating window. In this regard, there were simultaneous mud losses and oil and gas inflows during the circulation. The well was gradually replaced by oil and gas, regardless of the applied surface back pressure value in the MPD system. The mixing of the mud and reservoir fluid was accompanied by catastrophic contamination. As a result, the drilling mud became non - flowing plugging both the mud cleaning system and the gas separator. On the other hand, the plugging of the B1 formation with LCM did not bring any positive results. Bullheading the well followed by drilling with applied surface back pressure and partial mud losses gave only a temporary result and required a large amount of resources. An implementation of PMCD technology instead of MPD has been proposed as an alternative solution to the problem. This technology made it possible to drill the well to the designed depth (2904 - 3010 m interval). For tripping operations, as well as the subsequent running of the production liner it was necessary to develop an integrated plan for well killing and completion in extreme instability conditions. As a result of various killing techniques application, it became possible to achieve the stability of the well for 1 hour. Oil and gas inflows inevitably occurred when the 1 hour lasted. Based on these conditions, the tripping and well completion process was adapted, which in the end made it possible to successfully complete the well, run the liner and activate the hanger in the abnormally high-pressure reservoir.

Blast from the Past, Solving Severe Congealed Oil Problems by Combining Existing Solutions

2021 ◽  
Author(s):  
Tirza Hahijary ◽  
Aditya Yudha Kusuma ◽  
John Rizal Jenie
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Mechanical Damage ◽  
Oil And Gas Industry ◽  
Hot Water ◽  
High Rate ◽  
Fluid Mixture ◽  
Well Production ◽  
Coiled Tubing ◽  
Mechanical Devices

Abstract A mature field in central Sumatra, Indonesia, has been producing heavy oil for decades, and it has shown decreased production. The ESP, as the main lifting method, needs to be replaced more frequently due to mechanical damage by congealed oil. Many wells in that field were forced to be deactivated because of congealed oil plugging along the wellbore. The conventional method to tackle this issue is to pump hot water. This practice however did not give sustainable results after the treatment. The remedy of coiled tubing (CT) well cleanout with a wash nozzle has also not been considered successful because the congealed oil is too hard to penetrate. Furthermore, using mechanical devices such as CT milling tools has not been effective because the deposits stick to the mill. Considering the low-production-rate wells, high-rate fluid injection was proposed to meet cost criteria. Although the well was able to produce afterwards, production kept declining due to the production of congealed oil from the formation. A combination of high-pressure jetting tool and organic dissolver fluid was proposed as an alternative method to break the congealed oil. The method uses kinetic energy from the jetting tool to shatter the solidified oil by pumping brine. Afterwards, a fluid mixture composed of organic dissolver and additive is pumped to dissolve the remaining congealed oil. Following the treatments, the pilot well showed significant improvements. The treatment successfully revived well production after the well had stopped producing for more than 3 months. The flowback tank was filled with as much as 10-in.-deep broken oil residue. Such a solid removal has not been accomplished with any other technique. The well has been producing for more than 10 months without any pump issues, and production continues to increase. Another three well candidates with low productivity issues were treated with the same technique. All the wells delivered good results. If, in the future, the congealed oil accumulates again, high-pressure jetting and organic dissolver will be the first method used for remediation. All the wells treated with this approach have been producing significantly more than those treated using any other technique, well beyond the target set by the operator. This study discusses the benefits of combining the techniques of high-pressure jetting, organic dissolver, and high-rate injection to overcome severe congealed oil problems that impair well production. Details the approach are provided, and its effectiveness is compared to other former attempts to solve the congealed oil problem. This case also illustrates the importance of maintaining well interventions to improve production while meeting the cost criteria in this challenging time in the oil and gas industry.

scholarly journals A Novel Experimental Investigation of Cement Mechanical Properties with Application to Geothermal Wells

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3426 ◽  
Author(s):  
Catalin Teodoriu ◽  
Mi Chin Yi ◽  
Saeed Salehi
Keyword(s):  
Oil And Gas ◽  
Field Measurements ◽  
Strength Properties ◽  
Interfacial Bonding ◽  
Free Movement ◽  
Geothermal Well ◽  
Well Integrity ◽  
Well Design ◽  
Geothermal Wells ◽  
Cement Strength

Geothermal well integrity has proven to be of high importance, especially because the geothermal life span is expected to be longer than that of conventional oil and gas wells. Recent studies have demonstrated that cement-casing interfacial bonding is a classical well failure in such wells, but field measurements do not correlate with the simulations. We believe that this discrepancy is due to limitations of the simulation itself, which in most cases assumes a free movement of the casing after the interfacial bonding has been exceeded. Since the casing is cemented using a complex hardware package such as centralizer and other cementing components, the free movement of the casing is only possible when no-cement exists behind the casing. This paper proposes a novel experimental method to understand cement strength properties other than the standardized unconfined cement strength (UCS). The novel setup allows the measurement of interfacial bonding strength between cement and casing and the pure cement shear strength. The later becomes an important parameter as the interaction between casing couplings and cement will show. In the past, standard cement bending tests were designed to measure cement shear, but the value obtained from such tests is not relevant for the geothermal in situ casing-cement interaction, and thus the need for a new testing method arose. The new method is capable to mimic the interaction between the casing connection edges and the cement. We believe that the results presented within this paper will help engineers to validate their numerical simulations and to optimize the geothermal well design which will result in the increase of the well integrity for the life of the geothermal well.

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