Hydraulic Fracturing Of Formation Research Articles

НАПРАВЛЕНИЯ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ ГИДРОРАЗРЫВА ПЛАСТА В КАРБОНАТНЫХ ОТЛОЖЕНИЯХ МЕСТОРОЖДЕНИЙ РЕСПУБЛИКИ КОМИ И НЕНЕЦКОГО АВТОНОМНОГО ОКРУГА

The study presents an overview of the formation hydraulic fracturing application in carbonate deposits of fields of the Republic of Komi and Nenets Autonomous Okrug. The formation hydraulic fracturing technology has become widely used in carbonate reservoirs since 2012, with over three hundred well jobs performed. A significant share of residual recoverable reserves in carbonate deposits needs to be withdrawn; production rates need to be increased, inter alia, by way of the formation hydraulic fracturing. In the conditions of gradual deterioration of porosity and permeability of candidate wells, maintaining a steady level of technological effectiveness of hydraulic fracturing is ensured by implementing new technologies and optimizing standard processes. The hydraulic fracturing implementation issues are inextricably connected to the main issues of oilfield developments and specific structural features of carbonate reservoirs. Taking into account the specific structural features of carbonate reservoirs and existing development issues, the main objectives of the formation hydraulic fracturing have been determined: fracture conductivity increase; horizontal and vertical sweep increase; reduction of uncontrolled leakage of fracturing fluid; reduction of fracture height in conditions of adjacent water- and gas-saturated interbeds. Presently, a number of technologies has been successfully adapted and is used at the Republic of Komi and Nenets Autonomous Okrug sites. Due to the implementation of the integral approach to selection of the hydraulic fracturing technology modifications, taking into account the existing oilfield development issues and structural peculiarities of carbonate reservoirs, the reliable effectiveness of the method has been ensured in the conditions of deteriorating candidate wells; the technology application range has been extended. The study suggests expanding the range of the existing laboratory analyses to include such aspects as determination of stress intensity factor – fracture resistance and Biot’s poroelastic parameter, study of leakage rate dynamics in regard to various fracturing fluids, depending on the reservoir properties of core samples at given gradients, determination of dependence of proppants dynamic transfer on rheological properties of fracturing fluids and their filtration rates for various degrees of fracture model opening.

Новый метод снижения обратного выноса проппанта из трещины в скважину после проведения гидроразрыва пласта

Новый метод снижения обратного выноса проппанта из трещины в скважину после проведения гидроразрыва пласта

Efficiency Analysis of the Geological-Technical Activities in Severo-Ostrovnoe Field

The work is devoted to identifying the most relevant geological and technical measures carried out in Severo-Ostrovnoe field from the period of its development to the present. Every year dozens of geotechnical jobs (GJ) are carried out at each oil field-works carried out at wells to regulate the development of fields and maintain target levels of oil production. Today, there are two production facilities in the development of the Severo-Ostrovnoe field: UV1a1 and BV5. With the help of geotechnical jobs, oil-producing enterprises ensure the fulfillment of project indicators of field development (Mikhailov, N.N., 1992. Residual Oil Saturation of Reservoirs Under Development. Moscow, Nedra. p.270; Good, N.S., 1970. Study of the Physical Properties of Porous Media. Moscow, Nedra. p.208). In total, during the development of the Severo-Ostrovnoe field, 76 measures were taken to intensify oil production and enhance oil recovery. 12 horizontal wells were drilled (HW with multistage fracking (MSF)), 46 hydraulic fracturing operations were performed, 12 hydraulic fracturing operations were performed at the time of withdrawal from drilling (HW with MSF), five sidetracks were cut; eight physic-chemical BHT at production wells; five optimization of well operation modes. The paper analyzes the performed geological and technical measures at the facilities: UV1a1∦BV5 of the Severo-Ostrovnoe field. Four types of geological and technical measures were investigated: hydraulic fracturing, drilling of sidetracks with hydraulic fracturing, drilling of horizontal wells with multi-stage hydraulic fracturing, and physic-chemical optimization of the bottom-hole formation zone. It was revealed that two geotechnical jobs, namely, formation hydraulic fracturing (FHF) and drilling of lateral shafts in the Severo-Ostrovnoe field are the most highly effective methods for intensifying reservoir development and increasing oil recovery. SXL was conducted at 5 wells. The average oil production rate is 26.6 tons per day, which is the best indicator. Before this event, the production rate of the well was 2.1 tons per day. Currently, the effect of ongoing activities continues.

Сопоставительный анализ и интенсификация технологий гидроразрыва пласта (ГРП, ГДРП и ГДРП-К) при разработке пластов Д0, Д1 Алькеевской площади

Сопоставительный анализ и интенсификация технологий гидроразрыва пласта (ГРП, ГДРП и ГДРП-К) при разработке пластов Д0, Д1 Алькеевской площади

Планирование оптимальной длительности гидродинамических исследований скважин с наличием трещин гидроразрыва пласта (автоГРП) и горизонтальных скважин. Применение результатов для оценки достоверности гидродинамических исследований

Планирование оптимальной длительности гидродинамических исследований скважин с наличием трещин гидроразрыва пласта (автоГРП) и горизонтальных скважин. Применение результатов для оценки достоверности гидродинамических исследований

Влияние деформаций породы, возникающих при проведении гидроразрыва пласта, на прочность коллектора

Влияние деформаций породы, возникающих при проведении гидроразрыва пласта, на прочность коллектора

Оценка эффективности гидроразрыва пласта в нагнетательных скважинах

Оценка эффективности гидроразрыва пласта в нагнетательных скважинах

Оценка эффективности гидроразрыва пласта в добывающих скважинах и детализация по критериям применимости

Оценка эффективности гидроразрыва пласта в добывающих скважинах и детализация по критериям применимости

Применение оптического метода контроля за эффективностью гидроразрыва пласта на поздней стадии разработки Ромашкинского месторождения

Применение оптического метода контроля за эффективностью гидроразрыва пласта на поздней стадии разработки Ромашкинского месторождения

Прогнозирование упругомеханических свойств пласта по данным стандартного комплекса ГИС с целью оценки рисков развития трещины ГРП по вертикали пласта

Прогнозирование упругомеханических свойств пласта по данным стандартного комплекса ГИС с целью оценки рисков развития трещины ГРП по вертикали пласта

Моделирование трещины ГРП в лабораторных условиях

Моделирование трещины ГРП в лабораторных условиях

Laboratory research of fracture geometry in multistage HFF in triaxial state

Multistage hydraulic fracturing of formation (HFF) in wells with horizontal completion is an efficientmethod for intensifying oil extraction which, as a rule, is used to develop nontraditional collectors. It is assumed that the complicated character of HFF fractures significantly influences the fracture geometry in the rock matrix. Numerous theoretical models proposed to predict the fracture geometry and the character of interaction of mechanical stresses in the multistage HFF have not been proved experimentally. In this paper, we present the results of laboratory modeling of the multistage HFF performed on a contemporary laboratory-scale plant in the triaxial stress state by using a gel-solution as the HFF agent. As a result of the experiment, a fracturing pattern was formed in the cubic specimen of the model material. The laboratory results showed that a nearly plane fracture is formed at the firstHFF stage, while a concave fracture is formed at the second HFF stage. The interaction of the stress fields created by the two principal HFF fractures results in the growth of secondary fractures whose directions turned out to be parallel to the modeled well bore. But this stress interference leads to a decrease in the width of the second principal fracture. It is was discovered that the penny-shaped fracture model is more appropriate for predicting the geometry of HFF fractures in horizontal wells than the two-dimensional models of fracture propagation (PKN model, KGD model). A computational experiment based on the boundary element method was carried out to obtain the qualitative description of the multistage HFF processes. As a result, a mechanical model of fracture propagation was constructed,which was used to obtain the mechanical stress field (the stress contrast) and the fracture opening angle distribution over fracture length and fracture orientation direction. The conclusions made in the laboratory modeling of the multistage HFF technology agree well with the conclusions made in the computational experiment. Special attention must be paid to the design of the HFF stage spacing density in the implementation of the multistage HFF in wells with horizontal completion.

ABOUT SOME FACTORS DETERMINING THE EFFICIENCY OF FHF WITH INJECTION OF LARGE AMOUNTS OF SAND

Based on the results of laboratory and field tests of formation hydraulic fracturing (FHF) some basic factors are defined which influence upon the effectiveness of FHF technology involved the injection of large quantities of sand into the formation. These factors include a no strictly orthogonal trajectory of FHF fracture; abrasive destruction of initially round perforations; off-center positioning of quashhead shells inside the casing; sphericity and roundness of the proppant (sand) particles, etc.

SPECIFICS OF INVESTIGATION OF HORIZONTAL WELLS WITH FHF

The paper considers the distinctive features of study of horizontal wells with formation hydraulic fracturing.

FORMATION HYDRAULIC FRACTURING FLUID BASED ON CARBOXYMETHYL CELLULOSE: ITS ADVANTAGES AND LIMITATIONS, APPLICATION PROSPECTS

The article considers the advantages and limitations of hydraulic fracturing fluid based on carboxymethyl cellulose determined as a result of laboratory studies. As a result of testing the studied fluid manufacturing features compared with similar fracturing fluids it was determined that the fluid of interest can be effectively used as a fluid for formation hydraulic fracturing especially in low permeability reservoirs. This fluid is widely available and has a low cost. It can easily replace the foreign analogues.

Влияние геополитических факторов на состояние международных энергетических рынков (на примере США)

The authors claim that the Obama Administration used the so-called “shale gas revolution” to halt (at least partially) the process of de-industrialization of the country, which was a result of a structural crisis of its economy. While the advocates of liberalism claim that the market itself is capable of regulating the economic development, and the state should remain only a watchdog in this process both on the national and international level, the authors prove them wrong by analyzing the crisis of highly industrialized American economy, caused primarily by emergence of the rapidly developing IT-sector. After these two structures engaged in complex relations of dualism and confrontation, the need for strengthening the regulatory role of the state became evident. The U.S. government was unable to anticipate the crisis: it had been encouraging corporations to invest abroad, in a naive belief that it would strengthen the U.S. dominance in the world economy. Quite on the contrary, the IT outsourcing mechanism, which involved hiding the real profit from the American taxation and investing it into assets that considerably lost in value during the crisis, seriously damaged the American economy. While the Democratic Party’s relations with the oil-gas business were far from sympathetic (members of the Party have been standing for development of renewable energy and sustainable development for a long time), the Republicans advocated development of non-traditional oil-gas deposits (shale ones primarily). The corresponding amendments were supported by D. Cheney and passed through the Congress in 2005. This may be the reason why in his annual State of the Union address President Obama underlined the transitional character of the “shale revolution” and labeled it a “bridge” to the renewable energy strategy. Beginning of this “revolution” which “was to migrate all over the world” was announced by the Americans publicly at the International Gas Forum in Argentina (2009). In fact, no such “revolution” in the scientific sense of the term existed; it was rather decision of the Obama Administration to artificially create conditions for “cheapness” of shale gas on the domestic market, to stimulate business with subsidies and other incentives – combining it with a strict control of the U.S. Department of Energy and other government agencies in order to control, dispense and simply to delay the issuance of licenses for the construction of the export terminals, since a massive liberalization of exports could trigger an increase in domestic gas prices. The term “revolution” in this regard was used as a mechanism of pure propaganda, designed for the public and, first of all, for the competitors. It lacks any significant feature of a “revolution”: neither an original product but the same methane and oil, nor any qualitative breakthroughs in mining techniques: the two traditional long-known mining technologies were applied, namely the horizontal drilling and the hydraulic fracturing of formation. However, the process seriously damages the ecology: it is followed by environmental pollution, and in some cases, earthquakes and poisoning of the drinking water. Moreover, the costs of drilling shale wells are 5‑15 times higher than of the traditional ones; comparison in the recovery factor favors the traditional wells as well. The authors claim that Obama was bluffing in saying that the United States was ready to supply Europe with a significant quantity of shale gas. Advocates of U.S. hegemony, in the opinion of the researchers, would like to use the decline in oil prices as an instrument of pressure on Russia, so that it would no longer be an obstacle in their attempt to restore their world dominance. The image of the United States, until recently the undisputed world leader, has considerably deteriorated, and the nation has turned into the world’s biggest debtor stooping under the weight of all conceivable deficits. Washington apparently overlooked the obvious fact that globalization and the use of energy prices as an economic weapon can hit back like a boomerang. The authors argue that the key factor affecting pricing in the global energy industry is currently geopolitics, and the main “volcano” of turbulence on world markets is the United States of America.

EXPERIENCE OF USING THE NON-RADIOACTIVE MARKED PROPPANT AT FORMATION HYDRAULIC FRACTURINGIN THE ACHIMOV DEPOSITS OF THE FIELD URENGOYSKOE

The article discusses the issue dedicated to increasing the effectiveness of the formation hydraulic fracturing (FHF) implemented for the Achimov deposits, Urengoyskoe field, in the conditions of abnormal reservoir pressures. Based on the experience in FHF operations gained in the fields of West Siberia it is proposed to apply as a proppant the non-radioactive marked agent. It is shown that the offered NR proppant technology has proved to be a new and effective tool for estimation of the FHF fracture geometry, as well as a safe means due to absence of the radiation source together with the technological process simplicity and precision of the data obtained.

BRINGING THE WELLS BACK INTO OPERATION BY FORMATION HYDRAULIC FRACTURING

The article discloses the problem of bringing back into operation the wells having been suspended or out of operation, the technical state of which is unknown and the bottom-hole zone of the formation is heavily plugged. To bring the wells back into operation additionally to other technical solutions for a well deconservation it is necessary to recover the gas-dynamic bond of the reservoir with a well. For this it is offered to perform the formation hydraulic fracturing by two-fraction technology.

IMPROVEMENT OF OIL RECOVERY OF THE FLOODED LAYERS AT FORMATION HYDRAULIC FRACTURING

An approach has been found for realization of the formation hydraulic fracturing operations in the zones of the injected waters front taking into consideration this front type. The effectiveness of FHF in the zones of the formation with a static water injection front is proved.

EVALUATION OF THE STATE OF THE REPAIRED WELL NEAR BOTTOMHOLE ZONE BY SKIN-FACTOR

This article object of study is a bottomhole zone of exploration wells or repaired wells with positive values of skin-factor. The skin-factor is usually determined at processing of data of hydrodynamic studies of wells under unsteady-state conditions by measuring the pressure build-up or pressure draw-down curves. To improve the skin-factor and wells productivity various methods of production stimulation are applied. At the skin-factors values from 0 to +3 it is recommended to stimulate the bottomhole zone by vibrowave methods using jet pumps, and at skin-factor values from +3 to +5 to perform the formation hydraulic fracturing.