Operations conducted by petroleum industry generate an entire range of drilling waste. The chemical composition of drilling waste and its toxicity depend primarily on the geological and technological conditions of drilling, the type of drilled rock deposits and on the type and composition of the drilling mud used. In the course of drilling operations, drilling fluids are in constant contact with bacteria, fungi and other organisms infecting the mud. Pioneer species, capable of surviving and using the resources of this specific environment, are selected. For this reason, the effectiveness of microbiota survival on different types of spent drilling muds and in different dilutions with brown soil was measured. Spent drilling muds samples came from drilling operations in various regions of Poland, e.g. Subcarpathia, the Polish Lowland and Pomerania regions. Oxygen consumption after 96 h was around 20 μg·g^‒1 dry mass in soil or soil/drilling water-based mud mixture. Soil mixes contained 10 wt% synthetic base, mud had a higher oxygen consumption – 38 μg · g^‒1 dry mass. Oxygen consumption decreases sharply as the content of the spent synthetic base mud fraction increases. A higher concentration of spent SBM (35 wt%) reduced the aerobic metabolism by slightly more than 50%. A high concentration of reduced carbon decreased the respiratory quotient (RQ) value to 0.7. All the researched drilling waste shows microbiological activity. At the full concentration of drilling fluids and non-dilution options, the chemical composition (salinity, inhibitors, etc.) strongly inhibits microbiota development and consequently, respiration

During drilling through aquifers using the rotary drilling method with drilling fluid application, the phenomenon of formation clogging in near-well zone takes place. This leads to physical changes in pore spaces in consequence of the deposition solid phase particles originating from the drilling fluid. Due to this fact, filtration velocity in the clogged zones of the aquifer formation decreases, which results in increased pressure drawdown and decreased well hydraulic efficiency. Therefore, it causes a reduction of the well total capacity. The article consists of studies connected to the development of the mud which will constitute the basis for a complex mud system intended for hydrogeological drilling in different encountered geological conditions. In the framework of laboratory research, technological parameters of six, commonly applied in oil and gas industry, polymer agents as well as new agent developed at the Drilling, Oil and Gas Faculty AGH-UST in Krakow were examined. The undertaken studies showed that the new agent, marked as CAGEx, provides the required technological parameters and can be applied as a base for drilling muds intended for hydrogeological drilling. The undertaken industrial research of the new CAGEx drilling mud carried out while drilling water intake well, confirmed the great stability of its technological parameters as well as insignificant influence on rock permeability damage in filter zone. The water intake well is characterized by high hydraulic efficiency and does not require additional activation treatment.

In the last decade, Poland has become one of the most active markets for unconventional hydrocarbon deposits exploration. At present, there are twenty concessions for the exploration and/or discovery of reserves, including shale gas. The area covered by exploration concessions constitutes ca. 7.5% of the country’s area. Four main stages can be distinguished In the shale gas development and exploitation project: the selection and preparation of the place of development of the wells, hydraulic drilling and fracturing, exploitation (production) and marketing, exploitation suppression and land reclamation. In the paper, the concept of cost analysis of an investment project related to the exploration and development of a shale gas field/area was presented. The first two stages related to the preparatory work, carried out on the selected site, as well as drilling and hydraulic fracturing were analyzed. For economic reasons, the only rational way to make shale gas reserves available is to use horizontal drilling, either singly or in groups. The number of drilling pads covering the concession area is a fundamental determinant of the development cost of the deposit. In the paper, the results of the cost analysis of various types of reaming method with an area of 25,000,000 m2 were presented. Cost estimates were prepared for two variants: group drilling for three types of drilling pads: with three, five and seven wells and for single wells. The results show that, as the number of horizontal wells increases, the total cost of the development of the deposit is reduced. For tree-wells pad, these costs are 7% lower than in the second variant, for five-well pads they are 11% lower, and for seven-well pads they are 11.5% smaller than in the second variant. Authors, using applied methodology, indicate the direction of further research that will enable the optimization of shale gas drilling operations.

Hot point drills were carried through in the Hans Glacier (Spitsbergen). For that purpose a non-cored hot point drill of 700 wattage was constructed. It was used among others for installing the ablation-movement stakes, for hydrological observations and in the boreholes an ice temperature was controlled.

In Poland, the economic use of methane from coal seams has been recognized as one of the objectives of the „Energy Policy of Poland until 2030“. In Poland at the Upper Silesian Coal Basin, reconnaissance operations were initiated to collect methane from coal seams using drilling wells and hydraulic fracturing operations.

During these operations, noise emission can have a significant impact on the environment. In order to limit the negative impact of noise, well pads are usually located in undeveloped areas. However, in the European Union, the majority of hard coal deposits from which methane can be extracted are located in areas with a high population density.

This article presents the results of noise measurements carried out during hydraulic fracturing operations of coal seams and the results of calculations of the equivalent sound level during the daytime. Based on the analysis of noise emission, some recommendations are given regarding the location of planned new well pads in highly urbanized areas in order to meet the applicable standards of noise protection.

The aim of performed research was to evaluate weed seedbank in soil under the influence of four different winter wheat tillage systems. Winter wheat was grown in the following cultivation systems: A – monoculture with direct drilling into white clover mulch; B – monoculture with direct drilling into wheat stubble; C – monoculture with conventional tillage; D – crop rotation with conventional tillage. It was shown that pre-sowing wheat tillage had a more considerable effect on weed species and weed seedbank in soil than type of crop rotation. The least seedbank was observed when plough system was replaced by direct drilling. In the soil layer of 0–20 cm, under wheat no-plough tillage, 20.3% less weed diaspores wasfound compared to monoculture with plough tillage and by 40.1% lessthan in crop rotation. The plough tillage increased amount of weed diaspores in the whole plough layer, while direct drilling increased it only in 0–1 cm of soil layer. After direct drilling of wheat into stubble (B) the number of weed diaspores in 1 dcm³ of soil in 0–1 cm layer was over twofold higher than in direct sowing in mulch (A), and threefold higher than in crop rotation (D) and almost six times higher than in wheat monoculture with conventional tillage (C). Dominating weed species in the soil over the types of wheat cultivation systems were: Chenopodium album L., Amaranthus retroflexus L., Apera spica-venti L., Lamium purpureum L., and Viola arvensis Murr.

Petroleum products are complex mixture of compounds of varied biological properties. They can

cause harmful changes in contaminated ecosystems and threaten humans and living organisms as well. Bioremediation (including bioremediation stimulated by biogenic substances and inoculation with biopreparations

from autochthonous bacteria and fungi) can result in creation of metabolites of a varied structure and biological

activeness, which has been partly recognised. Some of them are more toxic than an initial substrate. Besides,

they might have mutagenic features and be responsible for cancer. Estimation of bioremediation effectiveness in

waste pits was completed with toxicological monitoring. It was led with the use of living organisms as biomarkers representing all trophic levels of a chosen ecosystem: producers, consumers and reducers. This process enables total estimation of natural environment conditions. The aim of the research was to determine the influence

of petroleum contaminants and indirect metabolites (produced during bioremediation) on soil biocenose. The

results of biotests (toxicity, phytotoxicity and genotoxity) have been taken into account. The following biotests,

prepared and produced by Microbiotest, have been applied: PhytotoxkitTM, Ostracodtoxkit FTM, acute toxicity

tests Microtox® Solid Phase and Ames mutagenicity tests. The obtained results enabled observation of changes

in toxic properties during purification of the soil taken from waste pits. In addition, it can be claimed whether

the areas are suitable for forest usage.

Stemming plugs are one of the widely used accessory in surface mining operations. Stemming plugs assist conventional stemming material in gas retention and help in better fragmentation and explosive utilization. Effective use of the stemming plugs results in economic benefits and enhance the efficacy of the project. Economic and productive viability of stemming plugs have been conducted in depth by different researchers. Addition of stemming plugs to a new system requires ergonomic challenges for operators conducting drilling and blasting operation. Induction of a newer product in already established system is subject to overall positive feedback. This work investigates ergonomics of three different stemming plugs introduced to a limestone quarry in Pakistan. The stemming plugs were evaluated based on extra time needed, workers feedback, failures during operation, recovery time after failure and number of extra equipment required to carry out the operation. Points based matrix was established with likeliness of each plug and based on overall scores stemming plug 1 was most acceptable followed by stemming plug 3. Stemming plug 2 was disliked by operation and did not reach the level of acceptability of operators. This work will help stemming plug making industry in adapting to best practices by incorporating ergonomics of plugs in designing. Literature shows no previous work on ergonomics of stemming plugs.

This work presents the methodology for analyzing the impact of ground vibrations induced during the drilling of gas/oil exploration wells on the surrounding constructions, as well as on humans and the natural environment. In the primary stage, this methodology is based on measurements of ground vibrations induced by a specific type of drilling system in the so-called reference site. In the next stage, ground vibrations are estimated in similar conditions to another design site, these conditions are assumed for a given drilling system, treated as a vibration source. In both sites, special seismic and geotechnical data are collected to construct numerical models for dynamic analyses. Finally, if it is required, a protection system is proposed with respect to the drilling technology and local conditions. The methodology presented has been tested on the terrain of an active natural gas mine used as the design site, and located in the southeastern part of Poland. The reference site was placed in the terrain of a working drilling system in similar conditions in the central part of Poland. Based on the results of numerical simulations, one may verify the different locations of the drilling rig in the design site with respect to the existing industrial structure. Due to the hazard from destructive ground vibrations, a certain vibroisolation system was proposed at the design site. Based on the results of numerical simulations one could rearrange the components of the drilling system in order to provide maximum security for the surrounding structures.

Plastic rocks can creep, therefore the knowledge of the rheological properties of the drilled formations is an important element of the drilling process and when choosing borehole designs. These properties of plastic formations also influence the way in which appropriate drilling technology and drilling mud properties are selected. The article presents the effect of basic rheological parameters of salt from the Fore-Sudetic Monocline deposit on the drilling of boreholes in the mining area of KGHM Polska Miedź, which in the future can be used as a good drilling practice to improve the safety and efficiency of drilling.

The process of drilling in plastic rocks may be hindered. Salt is a plastic rock and in the analyzed rock mass it is deposited at a considerable depth. The caprock exerts big loads on it, beside the temperature in the deposit intensifies the rheological properties of the rock. The creep process causes that the borehole contracts, therefore the knowledge about the rheological properties of the drilled rock is very important for establishing the safe time in which the well may remain uncased. The paper is devoted to the influence of basic rheological parameters of salt bed in the Fore-Sudetic Monocline on the process of drilling of a borehole in the area of KGHM Polska Miedź as these data can be used in drilling practice in the future.

This study attempts to evaluate the field performance of various mining equipment used at the development galleries of coal mines. These are hand-held and jumbo rock drills, and a roadheader used in mechanical excavation. For this purpose, the penetration rates of rock drills were monitored and measured in the field. The physical, mechanical, and drillability properties were determined through the collected samples in order to understand the complex interactions between the rock and bit/pick. The abrasive mineral content was also analyzed with XRD analysis to examine the wear on the cutting/drilling tools. Besides, the specific energy of the equipment was calculated relying on the operational parameters. A comparison of the monthly advance and production rates of the drilling rigs and roadheader was made. The relations among operating power, specific energy, and design of buttons/picks were investigated. It has been found that the average advance and production rates of the mining equipment are consistent with the penetration rate. The results verified that the roadheader used in mechanical excavation and the jumbo drill used in drilling and blasting technique are the machines maximizing the advance and production rates.

Drilling operations of the Cape Roberts Project took place between 1997 and 1999 offshore of Cape Roberts in the western Ross Sea, Antarctica. These were made possible due to a group effort by geoscientists from Australia, Germany, Italy, New Zealand, Great Britain, and the United States. The major goal of this undertaking was the recovery and analysis of sediment core, which was expected to provide a first East Antarctic record of the Early Cenozoic hothouse to icehouse climatic transition. This goal was not attained. Nevertheless, over the three seasons, a 1500 m long composite section was recovered, including a predominantly Early Oligocene to Early Miocene (34—17 Ma) glaciomarine succession. It was analyzed in terms of sediment physical properties, paleontology, tectonic structures and geophysics. This multidisciplinary investigation allowed detailed reconstruction of a significant portion of local environmental history, spanning a period of highly variable environmental conditions strongly affected by local glacier advance and retreat across the Victoria Land Basin margin.

The longwall mining system with fall of the roof is still the most common hard coal extraction system in Polish mining. Its utilization for selective coal seams’ mining results in the development of post-extraction gobs at different depths. Methane desorption phenomena from the coal seams in the stress release zones and migration of gas towards the area of operations, result in methane accumulating also after completion of coal exploitation. Methane which is not exploited from the gobs can migrate directly to the atmosphere e.g. through overlying layers, faults, workings or directly via an operated ventilation grid of an adjacent coal mine – contributing to the Greenhouse Gas effect. One of the methods to capture methane (Abandoned Maine Methane) from abandoned coal mines is to drill vertical wells through several post-extraction gobs from the surface.

This paper presents the results of drilling operations at the AGH-Wieczorek-1 well, where first time in Poland, down-the-hole-hammer (DTH) with casing-while-drilling (CwD) technology were used to drill through several post-extraction gobs. The AGH-Wieczorek-1 well with 440.0 m MD was successfully drilled without any complications. Finally, three post-extraction gobs and two coal seams were drilled. Additionally, results from drillability tests, which were performed during drilling operations, are presented.

The purpose of this research is to substantiate a technical solution for improving the working conditions for the thermal factor in the extraction of oil by the thermoshaft method using the mine refrigeration technology. The review of manufacturers and technical characteristics of refrigeration technology in Russia, CIS countries and Western Europe was conducted. It was shown that the use of a water cooling machine in the mine air conditioning system will reduce the air temperature in the oil production gallery to the required values and will allow to abandon the long-term construction of a surface stationary refrigeration station. Normalization of the thermal regime reduces the costs of benefits and compensation for work in harmful labor conditions and improves the quality of service of production wells by operators. The practical significance is that the proposed project for the introduction of air conditioning has a high level of profitability, and its payoff will occur in the second year of operation.

The results of drill stem tests made on the autochthonous Miocene deposits of the Upper Badenian - Lower Sarmatian age in the Carpathian Foredeep were analyzed. Reservoir tests were performed in open and cased holes, where inflows of formation water of varying saturation degree and sometimes contaminated with drilling mud filtrate, were observed. A total of 58 intervals, geophysically qualified as gas-bearing, were analyzed. Statistical analysis methods were used for determining the influence of the formation depth on the depth of deposition of the Miocene, and also dependence of initial back-pressure exerted on the reservoir during DST, on the depth of deposition of the reservoir. No correlation was found between water flow rate and initial differential pressure. A satisfactory correlation was obtained between hydrostatic pressure of water cushion in the tubing string and reservoir pressure for selected 22 the Miocene intervals in the Dębica region. In this region the pressure quotient php/pz broadly ranged between 0.05 and 0.57. Another correlation was noted between initial back-pressure and a depth at which pressure was measured and initial back-pressure, and formation water flow rate. The regression equations determined with statistical methods can be used for predicting values of formation pressure, initial value of back-pressure, formation water flow rate and initial differential pressure during DST. On this basis technological parameters of successive reservoir tests can be determined for in the analyzed area of the Carpathian Foredeep, particularly in the Dębica region.