A study on PDC drill bits quality

The quality of innovating PDC (Polycrystalline Diamond Compact) bits materials needs to be determined with accuracy by measuring cutting efficiency and wear rate, both related to the overall mechanical properties. An original approach is developed to encompass cutting efficiency and wear contribution to the overall sample quality. Therefore, a lathe-type test device was used to abrade specific samples from various manufacturers. Post-experiment analyzes are based on models establishing coupled relationships between cutting and friction stresses related to the drag bits excavation mechanism. These models are implemented in order to evaluate cutting efficiency and to estimate wear of the diamond insert. Phase analysis by XRD and finite element simulations were performed to explain the role of physicochemical parameters on the calculated quality factor values. Four main properties of PDC material were studied to explain quality results obtained in this study: cobalt content in samples that characterizes hardness/fracture toughness compromise, undesired phase as tungsten carbide weakening diamond structure, diamond grains sizes and residual stresses distribution affecting abrasion resistance

CFD Investigation on Fluid Flow Analysis in Fluid Separator

The analysis of fully developed flow in the two fluid separators is an important issue in the industry such as production, processing, and petrochemical. The role of the two fluid separator is to separate two different fluid by using an appropriate mechanism without changing the quality. In this study, we have reviewed different mechanisms of two fluid separations such as gravity sedimentation, centrifugation, and electro kinetics, etc. The current work focuses on the design aspect of a fluid separator with respect to geometry and thermal design. CFD has been used to simulate flow in a fluid separator and its results have been verified experimentally. Flow rates used in the simulation have different values in interval 0.1 LPM. The study shows the best performance of fluid separator with respect to shape and flow rates. The given work helps to co-relate various design of separator in the industry with laboratory separators

Contemporary aeolian processes in Europe

Aeolian processes nowadays belong to the most important exogenetic processes forming the European landscape. On the one hand, these processes are developing under natural conditions in the areas beyond the extent of forest and compact plant cover, i.e. in the far North (polar countries), in the semi-desert on the Caspian Sea, in the upper parts of mountains, on sea coasts, and on the other hand in anthropogenically transformed areas, i.e. mostly in arable land. The following types of contemporary aeolian processes in Europe are distinguished and described: 1) dust storms and aeolian dust deposition, 2) wind erosion of soils and dune deflation, 3) aeolian processes in river valleys, 4) aeolian processes in mountains, 5) aeolian processes on sea coasts. The first two processes (dust storms and wind erosion) are the most important. Their significance results from the common occurrence (Fig. 1) and real and potential intensity of these phenomena - including extreme ones. They can cause heavy economic losses

Ropa niesczerpana pionowym odwiertem ze stożkiem wodnym - ocena, prognoza, remediacja

Water invasion mechanism - called water coning - affects vertical wells completed above the Oil-Water contact (OWC) in oil reservoirs with bottom water. The objective of this study was to quantify the amount of by-passed oil for a variety of the bottom water well-reservoir systems with water invasion to wells and to assess feasibility of downhole water sink completions to reduce oil by-passing. A large statistical population of possible reservoirs with bottom-water has been created using databases of actual reservoir properties worldwide. Dimensional analysis coupled with Monte Carlo method allowed converting statistics of reservoir properties into dimensionless group distributions. Then, the amount of by-passed oil was correlated with the dimensionless groups using three--level full-factorial designed experiments conducted with a reservoir simulator. A reservoir - well system with bottom water was modelled using a commercial black oil simulator with two concentric radial layers of oil pay and the aquifer zone having different sizes and properties. The resulting dimensionless correlations determine the expected value of by-passed oil at the end of well's operation. The correlations are general as they cover a wide range of reservoir-well systems. When the correlations are coupled with the reservoirs' population the results show that, for example, more than 25 percent of movable oil volume could be by-passed in one half of all the bottom-water reservoirs. The study also identifies dimensionless groups that mostly control water invasion - the end-point mobility ratio and well spacing. The results also reveal two mechanism of water invasion: coning or uniform OWC advancement. Numerical reservoir simulation is also used to investigate the well completion's length and placement that would minimize oil bypassing and optimize recovery. Single completions of different penetration (length) are compared to dual well completions with Downhole Water Drainage/Sink (DWS), for new wells and marginal (watered-out) wells. The results show that the best completion strategy for both the new and the marginal wells is the use of (or intervention with) DWS completions. DWS would delay water breakthrough, stimulate oil inflow by reducing water saturation around the well, and maximize Net Present Value by accelerating recovery.Mechanizm napływu wody, zwany tworzeniem się stożka wodnego, wpływa na otwory wiertnicze wykonane powyżej kontaktu ropa-woda w złożach ropy naftowej z podścielającą wodą złożową. Celem badań było określenie ilości przepuszczanej bocznym obiegiem ropy naftowej w różnych układach denno-złożowych z napływem wód do otworu, oraz ocena możliwości takiego wykonania dna otworu, by ograniczyć tego typu przepływ ropy naftowej. Stworzono statystycznie istotną liczbę złóż z wodą podścielającą na podstawie baz danych istniejących na świecie złóż. Stosując analizę przestrzenną oraz metodę Monte Carlo, przetworzono dane złożowe na bezwymiarowe rozkłady grupowe. Następnie ilość rozchodzącej się ropy naftowej została skorelowana z bezwymiarowymi grupami na podstawie trójpoziomowych, pełnych badań prowadzonych w symulatorze złożowym. Modelowano układ złoże-otwór z wodą podścielającą, wykorzystując przemysłowy symulator naftowy z dwoma koncentrycznymi, promienistymi warstwami ropnymi oraz warstwą wodonośną o różnych rozmiarach i różnych właściwościach. Uzyskane bezwymiarowe korelacje określają przewidywaną wartość przepływającej ropy pod koniec okresu działania otworu. Korelacje są ogólne, gdyż obejmują szeroki zakres układów złoże-otwór. Badania korelacyjne wykonywane z uwzględnieniem dużej liczby złóż wskazują między innymi, że ponad 25% objętości ruchomej ropy naftowej mogło przedostać się do połowy wszystkich złóż wody podścielającej. Badania określają również bezwymiarowe grupy, które w większości przypadków kontrolują napływ wody: stosunek końcowego współczynnika ruchliwości ropy i wody oraz odległości między otworami. Wyniki wskazują również na występowanie dwóch mechanizmów napływu wód: tworzenie się stożka wodnego lub przemieszczającego się kontaktu woda-ropa. Numeryczne symulacje złożowe wykorzystuje się również do badania długości wykonanego otworu oraz jego umiejscowienia w celu zminimalizowania ucieczek ropy i zoptymalizowania wydobycia. Metoda pojedynczego udostępnienia na różnych głębokościach została porównana z udostępnieniem dwoma otworami z wgłębnym systemem drenażowym, dla otworów nowych i marginalnych. Wyniki wskazują, że najlepszą strategią w przypadku otworów nowych i marginalnych jest zastosowanie (lub pojedyncza interwencja) metody drenażu wgłębnego. Opóźni ona przebicie wody, będzie stymulować dopływ ropy naftowej przez ograniczenie nasycenia wodą w warstwach wokół otworu i maksymalizować bieżącą wartość netto przez przyspieszenie produkcji

Stratigraphy and sedimentology of the Bug loess (Pleistocene: Upper Vistulian) between Kiev and Odessa (Ukraine)

Documented type sections (Vyazivok, Stayky, Uman, Troitskoye, Altestovo, Roxolany and Lebedivka) provide a basis for Pleistocene stratigraphy between Kiev and Odessa, and have been used to characterise the heavy mineral composition and part of the light fraction of the Bug loess in this area. These sections document an almost complete succession of climatic change during the last 780 ka, worked out mostly using loesses and palaeosols though also in the case of the first two sections, of glacial deposits. The heavy mineral composition of the Bug loess in these sections documents five mineral groups on the basis of their resistance to weathering and susceptibility to deflation and aeolian transport. Radar charts with particular mineral groups indicate mineralogical and genetic trends in the loesses. Moreover, in some sections the light fraction of the loess investigated contains derived microfossils (mainly foraminifers) of Cretaceous age, indicating source areas for the loess-forming material, and constraining the palaeowind directions. The data obtained allow distinction of three accumulation zones of the Bug loess in this area, reflecting loesses derived from different source areas and transported by winds from different directions. In northern sections (zone A), the Bug loess was accumulated by winds blowing from the west and north-west. More to the south (zone C), the same loess was accumulated by winds from the east and south-east. Loess preserved in zone B, between these areas, could be accumulated by winds from either of these directions

Correlation of Pleistocene deposits in the area between the Baltic and Black Sea, Central Europe

The distribution, age and correlation of Pleistocene sediments (1.806–0.01 Ma) is presented for an about 1200 km long geologic cross-section that extends from the Baltic Sea to the Black Sea and crosses the eastern part of the Polish Vistula drainage basin, the Dniester and Upper Pripyat drainage basins of the Ukraine, and also parts of the Russian Kaliningrad District andMoldova. In the vicinity of Warsaw, the oldest Pleistocene deposits comprise preglacial fluvio-lacustrine sediments of the Otvockian (Eburonian) cooling and Celestynovian (Waalian) warming stages that equate in the south with the Berezan and Kryzhaniv horizons, composed of loessy clays, silts and red-brown palaeosol. Along the cross-section, deposits of 8 main glaciations correlate with a similar number of main loesses (Narevian–Ilyichivsk, Nidanian–Pryazovsk, Sanian 1–Sula, Sanian 2–Tiligul, Liviecian–Orel, Krznanian–Dnieper 1, Odranian–Dnieper 2–Tyasmyn, Vistulian–Valday) that are separated by 7 main intra-loess palaeosols that developed during the main interglacial periods (Augustovian–Shirokino, Małopolanian–Martonosha, Ferdynandovian–Lubny–Solotvin, Mazovian–Zavadivka–Sokal, Zbójnian–Potagaylivka, Lubavian–Lublinian–Kaydaky–Korshiv, Eemian–Pryluky–Horokhiv). The first three interglacials are megainterglacials, which possibly include cool intervals during which ice sheets did not advance beyond Scandinavia. All glaciations and loesses, as well as interglacials and palaeosols that are considered asmain climatostratigraphic units of the Pleistocene of Central Europe, are grouped into climatic cycles and megacycles that correlate with corresponding units of Western Europe

Well Placement Optimization through the Triple-Completion Gas and Downhole Water Sink-Assisted Gravity Drainage (TC-GDWS-AGD) EOR Process

Gas and downhole water sink-assisted gravity drainage (GDWS-AGD) is a new process of enhanced oil recovery (EOR) in oil reservoirs underlain by large bottom aquifers. The process is capital intensive as it requires the construction of dual-completed wells for oil production and water drainage and additional multiple vertical gas-injection wells. The costs could be substantially reduced by eliminating the gas-injection wells and using triple-completed multi-functional wells. These wells are dubbed triple-completion-GDWS-AGD (TC-GDWS-AGD). In this work, we design and optimize the TC-GDWS-AGD oil recovery process in a fictitious oil reservoir (Punq-S3) that emulates a real North Sea oil field. The design aims at maximum oil recovery using a minimum number of triple-completed wells with a gas-injection completion in the vertical section of the well, and two horizontal well sections—the upper section for producing oil (from above the oil/water contact) and the lower section for draining water below the oil/water contact. The three well completions are isolated with hydraulic packers and water is drained from below the oil–water contact using the electric submersible pump. Well placement is optimized using the particle swarm optimization (PSO) technique by considering only 1 or 2 TC-GDWS-AGD wells to maximize a 12-year oil recovery with a minimum volume of produced water. The best well placement was found by considering hundreds of possible well locations throughout the reservoir for the single-well and two-well scenarios. The results show 58% oil recovery and 0.28 water cut for the single-well scenario and 63.5% oil recovery and 0.45 water cut for the two-well scenario. Interestingly, the base-case scenario using two wells without the TC-GDWS-AGD process would give the smallest oil recovery of 55.5% and the largest 70% water cut. The study indicates that the TC-GDWS-AGD process could be more productive by reducing the number of wells and increasing recovery with less water production