Development of Alternative Drive Concepts for Down-the-Hole Hammer in Deep Drilling

Author(s):  
Franziska Lehmann ◽  
Matthias Reich

Hard rock drilling is facing increasing importance by using geothermal energy as a new energy source. Percussive drilling methods are generally well suited for drilling hard rocks. However, until now there is no drilling tool available on the market that uses percussive drilling methods and can be applied in deep boreholes in combination with common drilling muds. The aim of the DGMK project 733 is to develop a hammer drill which generates the impact energy downhole and works with conventional drilling mud. Seven different drive concepts were developed during the feasibility study. Demonstrators were manufactured for four of the seven drive concepts. The evaluation of the drive concepts showed that two of them have a high potential for the implementation in the field. These two concepts will be developed further to laboratory prototypes and were investigated at a test facility.

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Osei H

High demand for oil and gas has led to exploration of more petroleum resources even at remote areas. The petroleum resources are found in deeper subsurface formations and drilling into such formations requires a well-designed drilling mud with suitable rheological properties in order to avoid or reduce associated drilling problems. This is because rheological properties of drilling muds have considerable effect on the drilling operation and cleaning of the wellbore. Mud engineers therefore use mud additives to influence the properties and functions of the drilling fluid to obtain the desired drilling mud properties especially rheological properties. This study investigated and compared the impact of barite and hematite as weighting agents for water-based drilling muds and their influence on the rheology. Water-based muds of different concentrations of weighting agents (5%, 10%, 15% and 20% of the total weight of the drilling mud) were prepared and their rheological properties determined at an ambient temperature of 24ᵒC to check their impact on drilling operation. The results found hematite to produce higher mud density, plastic viscosity, gel strength and yield point when compared to barite at the same weighting concentrations. The higher performance of the hematite-based muds might be attributed to it having higher specific gravity, better particle distribution and lower particle attrition rate and more importantly being free from contaminants. The water-based muds with hematite will therefore be more promising drilling muds with higher drilling and hole cleaning efficiency than those having barite.


2020 ◽  
Vol 10 (8) ◽  
pp. 3533-3540
Author(s):  
Cheikh Bergane ◽  
Larbi Hammadi

Abstract In this study, the impact of VG69 organophilic clay on the rheological properties of gasoil-based drilling muds (invert emulsions) was investigated. The flow curves of gasoil-based drilling muds as a function of the dose of VG69 organophilic clay were analyzed by the Casson model. The addition of VG69 organophilic clay with a quantity range between 0 and 5 g in gasoil-based drilling muds induces an increase in the yield stress and the viscosity at an infinite shear rate of drilling muds. It is also proven that the addition of VG69 organophilic clay leads to an increase in the viscoelastic and thixotropic properties of the drilling muds. The study of the stability of gasoil-based drilling muds by centrifugation showed that for a quantity of VG69 organophilic clay lower than 3 g, the stability of the drilling muds increases and for a quantity of VG69 organophilic clay higher than 3 g, their stability decreases. The results obtained showed that the addition of 3 g of VG69 organophilic clay to the gasoil-based drilling mud increased the yield stress by 230%, the viscosity at an infinite shear rate by 3.4% and it improved the mud stability by 70%.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Dae-Ji Kim ◽  
Jaewon Kim ◽  
Booyeong Lee ◽  
Min-Seok Shin ◽  
Joo-Young Oh ◽  
...  

This study suggests a method for quantitatively estimating the drilling performance of the down-the-hole (DTH) hammer during percussive drilling of rock surfaces. A pneumatic dynamic model of the DTH hammer was developed that considers the mass flow rate relations representing the orifice opening areas of the air tube, the piston, and bit flushing channels. A drill bit motion model was developed to represent the dynamics of a drill bit impacted by a dropped piston and explain the impact stress propagation and rock-crushing mechanism. The rock-crushing effect of the drill button bit was measured through a piston drop test. The pneumatic hammer model and drill bit motion model were then combined in a prediction model to determine the impact efficiency according to different rock types (i.e., soft, medium-hard, and very hard). The drilling efficiency was defined as the input value of the prediction model, which was used to simulate the drilling performance of DTH hammers considering the rock type and dynamic effect of the drill bit. Finally, the simulation results were compared with the results of in situ drilling tests for verification.


Nafta-Gaz ◽  
2021 ◽  
Vol 77 (3) ◽  
pp. 152-163
Author(s):  
Bartłomiej Jasiński ◽  

Drilling deep holes or drilling to provide access to thermal waters places increasingly high demands on the properties of the drilling muds. Due to the very high temperature, it may be difficult to maintain the appropriate rheology of the drilling fluid during drilling, especially when an inflow of highly mineralized brines occurs. High temperatures significantly reduce the effectiveness of most of the polymeric agents currently used in the drilling muds technology, in extreme cases causing complete and irreversible damage to their structure. Polymers with ether bonds, which include starches and cellulose, are the most vulnerable. Based on the literature data, it can be concluded that the disadvantages of these polymers can be effectively compensated by the addition of synthetic polymers, e.g. sulfonated polymers. Another direction in improving the thermal resistance of drilling muds indicated in the literature is the use of carbon nanoparticles: graphene flakes and nanotubes. The article presents an analysis of the possibilities of improving thermal stability of drilling muds by using chemical agents that allow to maintain appropriate rheological and structural parameters and filtration at temperatures up to 130°C. During the tests, three types of chemicals were added to the polymer-potassium drilling mud at different concentrations. The impact of these modifications on technological parameters of the drilling mud was tested. Then, samples modified by the addition of selected agents were exposed to the temperature of 130°C for a period of 24 hours. After this time, the samples were cooled to 20°C, then their technological parameters were measured and compared with the results obtained before aging at high temperature, and based on the obtained results, the effectiveness of individual agents was assessed. Among the agents tested to protect drilling mud against the adverse effects of high temperature, the most beneficial effect was shown by potassium formate in combination with PoliAMPS.


Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.


2020 ◽  
Vol 12 (4) ◽  
pp. 1578 ◽  
Author(s):  
Hongxia Sun ◽  
Yao Wan ◽  
Huirong Lv

Exhaust pollution and energy crises are worsening worldwide. China has become the largest motor vehicle producer; thus, promoting the use of new energy vehicles (NEVs) in China has important practical significance. In this paper, considering the limited rationality of governments, NEV enterprises and consumers, we study the subsidy policy of the China NEV market using the evolutionary game and system dynamics (SD) methods. First, a tripartite evolutionary game model is developed and the replicator dynamics equations and Jacobian matrix are obtained. A SD simulation of the model was conducted to further clarify the impact of the initial market proportion and three variables used in the model. The results show that the initial market proportion affects the evolution speed but does not affect the evolution result when the three group players all choose a mixed strategy. For governments, they should not hastily cancel price subsidies provided to consumers; rather, they should dynamically adjust the rate of the subsidy decrease and increase the consumers’ extra cost for purchasing fuel vehicles (FVs). NEV enterprises should appropriately increase their investments in the research and development (R&D) of NEVs.


1998 ◽  
Vol 1 (06) ◽  
pp. 489-495 ◽  
Author(s):  
Tommy Warren ◽  
Jim Powers ◽  
David Bode ◽  
Eric Carre ◽  
Lee Smith

This paper (SPE 52993) was revised for publication from paper SPE 36536, first presented at the 1996 SPE Annual Technical Conference and Exhibition, Denver, 6-9 October. Original manuscript received for review 11 October 1996. Revised manuscript received 22 September 1998. Paper peer approved 23 September 1998. Summary A Wireline retrievable coring system for use with conventional drilling equipment is described. The coring system was developed and tested for application in evaluating coalbed methane prospects where a large quantity of core is required, and it is essential that the core is processed soon after it is cut. A drill plug allows for alternation between coring and drilling without tripping the drillstring. The system is particularly advantageous for coring long intervals, multiple zones relatively close together, or when the exact target depth is unknown. The system has been used to core more than 4940 m (15,057 ft) in Poland, Germany, and France, with a combined core recovery of 94%. In addition, the impact of varying rig costs on total savings is factored into the overall economic evaluation of the system. P. 489


1981 ◽  
Vol 38 (3) ◽  
pp. 268-274 ◽  
Author(s):  
Charles D. Derby ◽  
Jelle Atema

The effects of whole drilling muds on the normal activity of walking leg chemosensory neurons of the lobster, Homarus americanus, were examined using extracellular neurophysiological recording techniques. Exposure of legs for 3–5 min to 10 mg/L drilling mud suspended in seawater altered responses to food odors of 29% of the chemoreceptors examined (data pooled for the two drilling muds tested); similar exposure to 100 mg/L drilling mud resulted in interference with 44% of all receptors studied. The effects of both of these concentrations are statistically significant, although they are not different from each other. Interference was usually manifested as a marked reduction in the number of action potentials in a response. In one preparation, the exposure to drilling mud caused a change in the temporal pattern of the spikes without affecting the total number of spikes. Other chemosensory neurons were excited by 10 mg/L drilling mud itself. However, not all chemoreceptors are inhibited by these drilling muds since responses to feeding stimuli were recorded from the legs of lobsters that had been exposed to drilling mud for 4–8 d before the neurophysiological experiments.Antennular and leg chemoreceptors are important in eliciting normal feeding behavior in lobsters. Although behavioral assays have demonstrated that feeding behavior is altered following exposure to drilling muds and petroleum fractions, there is no conclusive proof for a causal relationship between chemoreceptor interference and behavioral deficits. The two techniques complement each other as pollution detection assays, perhaps reflecting a common interference mechanism.Key words: chemoreception, drilling mud, feeding behavior, lobster, pollution, neurophysiology


2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Marcin Lackowski ◽  
Marek Tobiszewski ◽  
Jacek Namieśnik

This work presents the construction solution and experimental results of a novel desorber for online drilling mud gas logging. The traditional desorbers use mechanical mixing of the liquid to stimulate transfer of hydrocarbons to the gaseous phase that is further analyzed. The presented approach is based on transfer of hydrocarbons from the liquid to the gas bubbles flowing through it and further gas analysis. The desorber was checked for gas logging from four different drilling muds collected from Polish boreholes. The results of optimization studies are also presented in this study. The comparison of the novel desorber with a commercial one reveals strong advantages of the novel one. It is characterized by much better hydrocarbons recovery efficiency and allows reaching lower limits of detection of the whole analytical system. The presented desorber seems to be very attractive alternative over widely used mechanical desorbers.


2014 ◽  
Vol 694 ◽  
pp. 163-168
Author(s):  
Liang Guo ◽  
Yun Liang ◽  
Xu Zhang ◽  
Xiao Tian Yang

With the rapid development of world economy, the energy crisis has become one of the urgent problems to be solved. Photovoltaic technology is a green new energy industry, no pollution is widely used all over the world. Typically, for photovoltaic component installation, only considering the utilization of components support cost and area, and the arrangement of components have not given enough attention. Photovoltaic module in use process will inevitably encounter the shadow, the shadow changes to make appropriate adjustments to the PV module arrangement can enhance the power generation capacity. Effect of the shadow on the photovoltaic system performance can be effectively used for photovoltaic component to bring help, is of positive significance. This study analyzed the villa model typical, and the rectangular shadow is modeling, in order to analyze the influence on the photovoltaic component. Through the conclusion of this study can determine the horizontal and vertical components of photovoltaic components which caused little damage, and provide a reference for future research of shadow and photovoltaic system performance.


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