The pdf file of this paper is in Russian. To purchase the paper in English, order SPE-116955-MS.
The article addresses a large area (a territory 100 km long and 80 km wide) encompassing several oil fields, including South Priobskoye, Chaprovskoye, Kondinskoye, Malokondinskoye, North Kondinskoye and West Kondinskoye. The breakdown of this huge and actually a single oil-and-gas bearing zone consisting of a series of sand lenses and containing 1.5 bln tons of recoverable reserves is rather tentative. The authors of this paper have been working in this area and participated in exploration, investigation and development of numerous fields within the Priobsky-Kondinsky zone. Due to complex geology of clinoform formations, low flow properties of the rocks, wide spacing of exploratory wells and seismic surveys, a number of fields situated in the southern part of the Frolovsky depression were brought into production 15 to 20 years later than expected. A significant engineering breakthrough in oil production occurred due to implementation of massive reservoir fracturing treatments and integrated approach to 3D seismic interpretation. These are the technologies that allowed successful development of low-permeability clinoform productive reservoirs within AS9-AS12 formations in all the fields discovered in this area. As of today, a great amount of 3D seismic surveys were shot in many license areas totaling over 3000 sq km. Production drilling and oil production in actually all the fields within the Priobsky-Kondinsky area involve massive frac jobs. Integrated interpretation of 3D seismic led to surprising results indicating the most complex geology of the Neocomian clinoform reservoirs including both tectonic processes associated with sediment slides, and formation of fans within turbide flows. Thorough insight into spatial position and forecasting of flow and storage properties of each sand body allows efficient drilling and development of low-permeability oil saturated reservoirs in the Priobsky-Kondinsky area.
A major exploration and production company operated Block 15 and unified fields Eden-Yuturi and Limoncocha from 1986 to May 2006, when the contract passed back to the Ecuadorian Government.
In 2004 a decision was made to implement an ESP Real Time Monitoring and Diagnosis system in order to optimize production and improve ESP operations. The system includes automation hardware equipment and a server-client software package.
The purpose of this paper is to give details about the benefits of remote monitoring and control of Electrical Submersible Pumps, and the real results achieved from using the ESP monitoring and diagnosis system to monitor, analyze, and remotely control ESP performance at Block 15. In this paper, we will highlight ways in which the ESP diagnosis system has enabled material improvements in operational efficiency at Block 15.
Brown-field experimental design techniques were applied to the Tengiz super-giant carbonate reservoir. This brown-field study combined experimental design, reservoir simulation, and available historical pressure and production data to develop proxies to predict the history match quality and oil recovery of equally probable reservoir realizations. The authors used experimental design techniques similar to those documented in Landa et. al.1 and King et al.2; however, the effort documented in this paper incorporated a much larger brown-field component and highly non-linear response surfaces required many more runs (control points) to generate reliable proxies.
The initial simulations runs included a folded Plackett-Burman design with a centerpoint run and sensitivity analysis runs which varied the input parameters that were known to affect the history match. The results from these runs were analyzed using regression analysis and ANOVA techniques to determine the most significant factors and to understand the complexity of the response surfaces. With this knowledge, D-optimal runs were designed and run to better understand the effect of the interaction of the significant factors on the response surfaces. Additional sensitivity analysis runs were also made to further define the effect of the two most important factors on the response surfaces: OOIP and reservoir transmissibility. With a total of 107 unique runs, the authors were able to develop five proxies to assess history match quality and one proxy to predict oil recovery.
With the developed proxies, the authors used Monte Carlo techniques to generate equally probable reservoir/development scenarios. By using the history match quality proxies the authors were able to filter out combinations of subsurface parameters that caused unacceptable deterioration in the history match. The use of the five unique filters allowed the authors to significantly reduce uncertainty relative to the unfiltered simulation results. The results from this work were supported by material balance studies.
I. NEW PUMPING EQUIPMENT
B. A. Erka, A. A. Dvinin
In view of oil production restraints, such as high viscosity, high gas-oil ration, entrained solids, etc., current oil production methods are limited because low-pressure area is required at the submersible pump inlet for the subsequent compression and pumping of reservoir fluid into tubing.
The implication of this new artificial lift method is that vane pump is used instead of submersible pump (Fig.1) , as vane pump retrieves reservoir fluid without low-pressure area created at the pump inlet as the working elements (vanes) can operate directly in reservoir fluid.
We applied Experimental Design methodologies to evaluate development options in a Siberian field with major uncertainties in the geological, reservoir and financial parameters. Our approach, used for the first time in Russia, demonstrates an inverted 7-spot injection pattern is expected to yield 11% more oil than a line drive - identified by conventional evaluation methods. Of more significance, for decision making, the analysis predicts that the expected net present value (NPV) of this pattern is 46% more than the pattern proposed previously.
The primary reservoirs consist of stacked fluvial, delta distributary channel and mouth bar sands. Although exploration tests confirmed oil rates exceeding 120 tonne/day, the location and orientation of the individual sand bodies could not be mapped from existing seismic. Recognising this was a risk to project success, we developed an Experimental Design technique for quantifying the uncertainties in oil rate predictions. The major stages were:
Our experience shows that Experimental Design techniques integrated with advanced computer technology can cut evaluation times from months to weeks. More importantly, they give unbiased probabilities of production profiles and NPV so that downside risks can be quantified.
This paper is dedicated to the key engineering solutions concerning development of the Kumzhinskoye field. The focus is put on the field development principles related to its complex environmental history.
The challenge we face in this field results from an accident that occurred while drilling well 9 in the crest of the structure due to failure to meet regulations on integrated gas and gas-condensate well testing procedures with regard to well production rates through orifices of certain size and duration of well production at those rates. Abnormally high gas flow rates amounted to 807 thousand m3 per day. The problem and severe pollution near the well resulted from a nuclear explosion 1500 m deep aimed at shearing the wellbore due to displacement of a rock mass. However, instead of the accident remediation the explosion increased the area of gas and condensate blowouts. As a result, a huge damage was inflicted to the environment and the Pechora river delta ecosystems. Exploratory wells are exposed to aggressive hydrogen-sulfur medium. Poor cementing creates the conditions for gas crossflows from natural reservoirs to overlying water bearing zones forming human-induced gas deposits. Accident remediation took almost 15 years.
It is important to realize that environmental challenges of this field are so huge that it is useless to handle them from the surface. Solution of environmental problems requires an integrated approach to the field development.
First, the primary reservoir is to be depleted to make its pressure drop below the pressure in the secondary induced deposits (200 Atm) and shut down the upward gas migration. Second, shallow slim holes are to be used to deplete induced deposits. To minimize the environmental damage, we are planning to ensure complete gas recovery using only 18 horizontal wells. We shall drill those wells from only 2 well pads minimizing land allotment for industrial purposes. In addition, these well pads are located in dry elevated areas outside the national reserve territory.
The work was performed with the aim to take part in a tender for the right to use the subsurface for geological exploration and production of hydrocarbon resources in a field situated within the Nenets autonomous district. The Kumzhimnskoye field ranks among the largest ones in terms of gas reserves. High ratio of proved reserves relative to total reserves amounting to 80%  shows a high exploration maturity of this field ready for start of the field development.
Hydrocarbon exploration and production in environmentally sensitive areas is associated with complex climatic and geological conditions of the Arctic region, presence of permafrost and a great number of swamps, rivers and lakes.
The focus was put not only on the field geology analysis but also on solution of environmental issues related to remediation of human-induced damage inflicted during the previous exploration activities. It was suggested to continue with the analysis of the field and its particular features using the most advanced high technologies allowing minimization of environmental impact.
Before the mid-1990s, the main goal of hydraulic-fracturing operations in Russia was preventing near wellbore damage. Typical fracturing treatments used a crosslinked polymer-based gel as carrier fluid to place 5 to 20 MT of proppant into the formation. Because of the results, a new phase started, whereby "real?? production enhancement treatments achieving skins of well beyond -4 were pumped with proppant volumes from 50 to over 100 MT. Because of Russian oil production practices at the time, it became apparent that the hydraulic fracturing technology combined with drilling horizontal wells increased production and was therefore beneficial to the Russian economy.
When the optimization process started, quality control in the field became mandatory in addition to an enhanced focus on health, safety and environment. Service companies focused on cleaner fluids with less polymer loadings and better breaker systems. Prejob, on-the-job, and postjob quality control procedures were developed specifically for the Russian environment and reached a standard unlike anywhere else in the world. The number of unwanted screenouts was reduced significantly by following proper perforating practices and optimizing the treatments designs in real time. The new goal was a skin of -5, and the design process was optimized to achieve this number by designing each job to achieve optimum production for the given reservoir parameters, especially permeability. Treatments of 300-400 MT are not uncommon these days for low permeability reservoirs with a large reservoir height sometimes covering several zones.
This lead to the optimization process that is currently practiced. Because many sandstone reservoirs, particularly in Siberia, are laminated, the vertical permeability is often an order of magnitude or more lower than compared to the horizontal permeability. Several times, horizontal wells did not yield the expected results. Hydraulic fracturing treatments placed in the horizontal wellbore can be the solution for further production optimization. This paper describes how this can be established through several techniques.
Hydraulic fracturing includes propped hydraulic fracturing in both oil and gas reservoirs, as well as carbonate fracture acidizing. This paper discusses propped hydraulic fracturing in oil reservoirs. Covering propped hydraulic fracturing in gas reservoirs, although still at the beginning stages, could reveal enough material for a paper on its own. However, carbonate fracture acidizing is not frequently used.
Nowadays, hydraulic fracturing is one of the most effective ways of low-permeability layered reservoirs management. About half of the oil reserves, remained in Western Siberia today, are concentrated in such reservoirs. The field experience and engineering calculations show that without fracturing the largest part of this oil would be left in the Earth forever. That is why we can classify hydraulic fracturing as a method of oil recovery enhancement.
The reduction of multi-zone fracturing time cycle is an important part of asset management and cost optimization for the large multi-layer oil fields developing with the help of hydraulic fracturing.
This paper was also presented as SPE 117157 at the Abu Dhabi International Petroleum Exhibition and Conference, 3-6 November 2008, Abu Dhabi, UAE.
The pdf file of this paper is in Russian. To purchase the paper in English, order SPE-116848-MS.
This paper describes the current data architecture that Saudi Aramco has recently implemented for real-time drilling and completions (D&C) information. This new architecture enables us to make wider use of our monitoring and collaboration centers through a common approach. It also allows us to leverage the evolving WITSML standard more effectively in our drilling operations.
Saudi Aramco uses many different service organizations to deliver its global drilling and completions agenda. In the past, this has resulted in a lack of stability and standardization in real-time information flow. We have been unable to share data and expertise readily between different operating centers. Applying a common approach to information access on a global basis has enabled us to streamline our operations and make wider use of emerging analysis, monitoring and collaboration technologies.
Real-time technologies have been utilized to capture, monitor and analyze drilling data from rig sites so that critical decisions can be made real-time in order to help reduce and eliminate borehole problems, thus reducing non-productive time. That includes high-tech rigs, business continuity solutions for real-time information, collaboration tools and real-time data visualization systems.
Our aim has been to implement a standard D&C information architecture. Our adoption of WITSML was the vehicle which allowed this to happen. However, we still believe that over the next years it is likely that there will be much more of a challenge to support open connectivity between different vendors and services supporting the increasing drilling and completions functions.
WITSML (Wellsite Information Transfer Standard Markup Language) is a continually developing industry standard for the transmission of real-time, historical and contextual drilling and completions information.
The development of this standard is unique in that it brings together specialists from across a broad spectrum of the upstream oil and gas industry, drawn from both from the operator and service company knowledge pools, thereby accelerating the evolution of a mechanism that will finally allow a true seamless exchange of data between data acquisition providers and energy company consumers.
The WITSML standard is managed by Energistics (www.energistics.com) on behalf of the members.
The pdf file of this paper is in Russian. To purchase the paper in English, order SPE-117402-MS.
In the modern world the development of informational technologies is going on at a breakneck pace.
Often the company that starts implementing them in the business earlier surpasses its competitors by far in all key indicators. Based on this, the decision to develop and deploy the state-of-the-art information technology in OFS subsidiaries was taken. This system was named INFORM.
INFORM system is a multi-functional intranet portal that stores and processes important operational information of OFS subsidiaries. INFORM consists of key sections, such as Drilling, Workover, Technical Maintenance and Repair, Quality Management System, Operational Forum, and Training Programs.
Thanks to INFORM, rig toolpushers can enter daily operations reports, and HQ managers can review operational performance at all wells based on these data. The portal has a great number of reference operational data, Field Operations Manuals, and the results of rig audits. The interactive map of Russia can show you the location of each rig and get the contact data of every toolpusher. All operational incidents in every subsidiary are stored in INFORM, so toolpushers have the opportunity to prevent them in their own crews. INFORM's Operational Forum has important operational issues discussed and information shared. The information contained in INFORM is Company's property: all TNK-BP users have the access to this site, while the operational data of INFORM is available only for the registered users.
So INFORM is the system we have designed to allow OFS to collect, organize and share knowledge which allowed for accelerating the process of decision making in OFS.
While implementing INFORM project team achieved next results:
- Evaluated the availability and quality of communication channels at the rigs, In case no communication channels are available, they were built with the optimum capacity using satellite technologies
- Purchased and installed the required server and computer equipment in the subsidiaries and rigs.
- Held a tender among IT companies on the development of System according to TNK-BP and OFS standards
- Developed the interface of the future portal
- Entered all data into INFORM. Obtain data from the services: HSE, HR, Quality, Technology department, etc.
It's common knowledge that every commercial company strives at optimizing its business processes to minimize costs and maximize profit. Such optimizations take place during any operation of a business structure, it's an objective and normal evolutionary process. Subject to the economic or political conditions, the pace of the processes may be either slow, or fast, or they may come to a total ground still.