The Use of Hydraulic Completion Snubbing Units HCU in Long Laterals in U.S. Shale Plays

Coiled tubing units (CTU) have been used to drill-out frac plugs in shorter horizontal shale wells for the last decade, but coil has mechanical limitations. The new innovative technology of Hydraulic Completion Snubbing Units (HCU) is gaining popularity across North and South America to drill-out frac plugs in long lateral, high-pressure, and multi-well pads. The HCU is designed for drill-outs and interventions where coil may not be the best option. This paper will summarize the recent evolution of the HCU system. Case histories will be provided from the Appalachian and Permian shale plays. The latest HCU consists of a stand-alone unit that mounts on the wellhead after completion. The primary components include the jack assembly, a gin pole, traveling/stationary slips, a redundant series of primary/secondary blowout preventers, a rotary table, power tongs, and an equalize/bleed off loop. Tubing up to 5 ½" is used to carry a downhole motor, dual back pressure values, and the drill bit. Slickwater is used for the drilling fluid to carry out parts from the frac plugs while the tubing is rotated via the jack rotary table. Torque and drag modeling are performed to guide downhole expectations that allow most wells to be drilled in one trip and with one bit without short trips back to the heel or bottom- hole vibration assembly tools. Finally, a remote telemetry data acquisition system has been added that summarizes the drilling data and key performance indicators. In 2016, a North American operator drilled and completed the first super lateral in the Appalachian Basin, setting the completed lateral record at over 18,500 ft. Since then, many operators have been routinely drilling laterals between 12,000 ft and 16,000 ft. HCU technology has been used in the longest laterals in onshore North America, including the lower 48 U.S records for completed lateral length (LL) at 20,800 ft and the total measured depth (MD) record at 30,677 ft. The average lateral contains between 60 to 90 plugs and can be drilled out in 3.5 to 4.5 days. The record number of plugs drilled out by an HCU is 144 and took 5.2 days. High-pressure wells are also routinely encountered where pressures range from 3000 to 8000 psi during operations. Operators are achieving faster drilling times per plug, less chemical usage, faster moves between wells, and running tubing immediately after the drill-out, thus eliminating the need for a service rig. Operator's desire to reach total depth with the least risk and as cost-efficiently as possible resulted in the HCU gaining market acceptance. This paper will showcase the novel evolution of the HCU system that has enabled it to be a safe and effective option for interventions outside of just frac plug drill-outs such as fishing for stuck/parted coil or wireline and installing production tubing/artificial lift systems.

Aspects of Energy Saving of Oil-Producing Enterprises

Increasing energy efficiency is included in the UN Sustainable Development Goals (SDGs) to be achieved by the year 2030. Enhancing energy efficiency is also one of the priority areas for improving the operational efficiency of any oil production enterprise. The energy management system of enterprises has been founded and implemented on the basis of the international standard ISO 50001:2018 and it works successfully. The energy efficiency strategy is formulated in the energy policy and integrated into the business model of the companies. Companies receive significant energy savings in the exploration and production segments through technical, technological, and organizational measures. This article shows the main directions for improving the energy efficiency of the artificial lift well stock and the results of their implementation. The main constraints on the implementation of the energy efficiency policy of oil-producing enterprises have been identified and directions for improvement of energy-saving structure have been proposed. The article proposes strategic-level classification of energy-saving measures, which is based on assessment and comparison of implementation costs, payback period, and takes into account investments into artificial lift technology, therefore allowing investment priorities in the energy management sphere to be distinguished. Advanced directions for investment in oil-production technology have been identified, and an algorithm of development and implementation of key indicators of energy consumption efficiency has been proposed.

System Analysis and Application of Combined System of ESP and Gas Lift

With the development of deep-buried reservoirs and offshore fields, many prominent problems have been encountered by the use of conventional single artificial lift technologies, which can not meet the requirements of production and may cause frequent workovers. The combination of electrical submersible pump (ESP) and gas lift system (GL), taking advantages of flexible pump rate, relative long workover intervals and simple composition of tubing strings, is considered to be a better solution. The design of ESP-GL combined system is more complicated, referring to the distribution of pressure, temperature and viscosity fields of multiphase flow in the tubing string. In this article, based on the performance curves of lift devices and oil well, the design approach of the ESP-GL combined system based on nodal analysis is established with an example calculation. An optimization design approach of the combined system is then developed by intelligent algorithms, considering some key operating parameters, e.g. pump drainage rate, ESP depth, ESP stages, valve depth and gas injection rate, to find the optimal operating condition of the system. At the same time, the combined lifting system has been successfully applied in some pilot tests in China and Vietnam reporting to have production increments, which suggests a good potential for the application of the ESP-GL combined system in deep fields.

Quadrant Mapping Artificial Lift Concept

This paper outlines a concept for monitoring performance of artificial lift performance such as electrical submersible pump (ESP), hydraulic pumping unit (HPU), sucker rod pump (SRP) and progressive cavity pump (PCP), for a large number of wells. The objective is to generate simplified monitoring performance of artificial lift with a huge number of wells on one page by creating quadrant mapping consisting of two coordinates with x axis representing pump efficiency and y axis showing pump submergence. We made a four-quadrant limit by pump efficiency (50%) and submergence (200 m). Optimum wells will show on range pump efficiency above 50% and submergence below 200 m, and 3 other quadrants are classified as artificial lift problems, well potential and sizing/design problems. By using the quadrant mapping concept, we can generate performance of artificial lift for 1500++ wells in one page, and this mapping consists of four quadrants (quadrant 1, quadrant 2, quadrant 3 and quadrant 4), quadrant 1 (Submergence above 200 meter and lifting efficiency below 50%) showing wells which have artificial lift problem, quadrant 2 (Submergence is above 200 meters and efficiency is above 50%) showing well which have potential to increased production, quadrant 3 (Submergence is below 200 meters and efficiency is above 50%) showing the optimum wells operation and quadrant 4 (Submergence is below 200 meters and efficiency is below 50%) showing the wells which required to re-sizing/re-design artificial lift. This quadrant mapping can be shown to Engineers, manager's and shareholder to show overall performance and classification detailed problems to create a troubleshooting, optimization program to increased oil production, run life artificial and result in better production performance. This mapping also helps petroleum engineers to get a better field view and create priorities and program optimization based on the quadrant mapping result and classification.

Numerical Simulation of Gas Lift Optimization Using Artificial Intelligence for a Middle Eastern Oil Field

Artificial lift techniques are a highly effective solution to aid the deterioration of the production especially for mature oil fields, gas lift is one of the oldest and most applied artificial lift methods especially for large oil fields, the gas that is required for injection is quite scarce and expensive resource, optimally allocating the injection rate in each well is a high importance task and not easily applicable. Conventional methods faced some major problems in solving this problem in a network with large number of wells, multi-constrains, multi-objectives, and limited amount of gas. This paper focuses on utilizing the Genetic Algorithm (GA) as a gas lift optimization algorithm to tackle the challenging task of optimally allocating the gas lift injection rate through numerical modeling and simulation studies to maximize the oil production of a Middle Eastern oil field with 20 production wells with limited amount of gas to be injected. The key objective of this study is to assess the performance of the wells of the field after applying gas lift as an artificial lift method and applying the genetic algorithm as an optimization algorithm while comparing the results of the network to the case of artificially lifted wells by utilizing ESP pumps to the network and to have a more accurate view on the practicability of applying the gas lift optimization technique. The comparison is based on different measures and sensitivity studies, reservoir pressure, and water cut sensitivity analysis are applied to allow the assessment of the performance of the wells in the network throughout the life of the field. To have a full and insight view an economic study and comparison was applied in this study to estimate the benefits of applying the gas lift method and the GA optimization technique while comparing the results to the case of the ESP pumps and the case of naturally flowing wells. The gas lift technique proved to have the ability to enhance the production of the oil field and the optimization process showed quite an enhancement in the task of maximizing the oil production rate while using the same amount of gas to be injected in the each well, the sensitivity analysis showed that the gas lift method is comparable to the other artificial lift method and it have an upper hand in handling the reservoir pressure reduction, and economically CAPEX of the gas lift were calculated to be able to assess the time to reach a profitable income by comparing the results of OPEX of gas lift the technique showed a profitable income higher than the cases of naturally flowing wells and the ESP pumps lifted wells. Additionally, the paper illustrated the genetic algorithm (GA) optimization model in a way that allowed it to be followed as a guide for the task of optimizing the gas injection rate for a network with a large number of wells and limited amount of gas to be injected.

Deployment of State-of-the-Art Horizontal Pumping System HPS Technology in Two Water Wells to Avoid ESP Workovers

The objective of this paper is to present the findings obtained from a detailed engineering evaluation resulting from trial testing two state-of-the-art surface horizontal pumping systems (HPS's) in two water supply wells. The two horizontal pumping systems were deployed as an alternative to downhole electrical submersible pumps (ESPs) to provide the benefits of eliminating ESP workover costs, modularity regarding wellsite deployments, and enhanced maintenance operations. For this trial test evaluation method, two HPS's were deployed to boost water production to the water injection plant (WIP). To ensure a thorough evaluation, the trial test well candidates were designed to accommodate both a subsurface ESP as well as a surface HPS to provide an accurate comparison, and representation, between the different artificial lift methods. The trial test and comparison method described in this paper focused primarily on the following items; maintenance and well intervention requirements, evaluation of operational availability, including potential for cavitation and effects of interference, maximum production rates, as well as root cause engineering evaluations for mechanical seals and cooling unit auxiliary motors. Various best practices and mitigation measures were identified and are presented in this paper. With regard to the results, it was observed that each artificial lift method comprised a set of advantages and disadvantages. The decision on which type of technology to use can be dependent on several factors. Overall, the HPS's demonstrated the ability to supply water production to the WIP. The HPS did experience operational challenges in providing higher production requirements. Additional challenges were also observed in the sealing mechanism as well as the auxiliary cooling unit. Precautionary pump tripping automated protocols were taken to prevent pump cavitation due to sub-optimal intake pressure resulting from possible interference. The HPS, unlike the ESPs, did not require any workover as it is located at the wellsite and therefore resulted in substantial cost savings and was easy to maintain due to its surface application. In summary, this paper adds a new and very beneficial evaluation of HPS's, and highlights best practices and lessons learned to the existing body of literature. The new information discussed in this paper is highly beneficial to engineering selections of artificial lift methods and to the successful implementation of HPS's in the industry.

Artificial Lift Optimization for Shallow Carbonate Magwa and Ostracod Formations with Massive Propped Fractures

Objectives/Scope: The Magwa and Ostracod formations are tight and highly fractured carbonate reservoirs. At shallow depth (1600-1800 ft) and low stresses, wide, long and conductive propped fracture has proven to be the most effective stimulation technique for production enhancement. However, optimizing flow of the medium viscosity oil (17-27 API gravity) was a challenge both at initial phase (fracture fluid recovery and proppant flowback risks) and long-term (depletion, increasing water cut, emulsion tendency). Methods, Procedures, Process: Historically, due to shallow depth, low reservoir pressure and low GOR, the optimum artificial lift method for the wells completed in the Magwa and Ostracod reservoirs was always sucker-rod pumps (SRP) with more than 300 wells completed to date. In 2019 a pilot re-development project was initiated to unlock reservoir potential and enhance productivity by introducing a massive high-volume propped fracturing stimulation that increased production rates by several folds. Consequently, initial production rates and drawdown had to be modelled to ensure proppant pack stability. Long-term artificial lift (AL) design was optimized using developed workflow based on reservoir modelling, available post-fracturing well testing data and production history match. Results, Observations, Conclusions: Initial production results, in 16 vertical and slanted wells, were encouraging with an average 90 days production 4 to 8 times higher than of existing wells. However, the initial high gas volume and pressure is not favourable for SRP. In order to manage this, flexible AL approach was taken. Gas lift was preferred in the beginning and once the production falls below pre-defined PI and GOR, a conversion to SRP was done. Gas lift proved advantageous in handling solids such as residual proppant and in making sure that the well is free of solids before installing the pump. Continuous gas lift regime adjustments were taken to maximize drawdown. Periodical FBHP surveys were performed to calibrate the single well model for nodal analysis. However, there limitations were present in terms of maximizing the drawdown on one side and the high potential of forming GL induced emulsion on the other side. Horizontal wells with multi-stage fracturing are common field development method for such tight formations. However, in geological conditions of shallow and low temperature environment it represented a significant challenge to achieve fast and sufficient fracture fluid recovery by volume from multiple fractures without deteriorating the proppant pack stability. This paper outlines local solutions and a tailored workflow that were taken to optimize the production performance and give the brown field a second chance. Novel/Additive Information: Overcoming the different production challenges through AL is one of the keys to unlock the reservoir potential for full field re-development. The Magwa and Ostracod formations are unique for stimulation applications for shallow depth and range of reservoirs and fracture related uncertainties. An agile and flexible approach to AL allowed achieving the full technical potential of the wells and converted the project to a field development phase. The lessons learnt and resulting workflow demonstrate significant value in growing AL projects in tight and shallow formations globally.

Modern Drilling and Completion in Contradiction of New Artificial Lift Method Concept

In challenging times of 2020 and inconsistency with the background of a low-oil-price environment, innovative ideas needed to give a second life to all available resources such as unconventional, shallow, depleted, mature, heavy oil and by bypassed oil with a cost-effective manner (usually innovation created to fit needs). U-shaped well a combined with pigging lifting (conceptual study for new artificial lift method) is one of the selected scenarios studied under the objective of innovative, low-cost techniques to overcome many projects challenges. U shaped well accompanied with a new pigging artificial lift method are new concept studied in this lab work. Conceptual model presents many benefits of this new application such as solving most of the current wells and production challenges. The study reflects more well control with two paths, better well stimulation, low fracturing pressure and double rates, inject and lift chemical for clean without intervention, double well life "additional strings", new recompletions without rig, two horizontal side used for production or injection, step change for reservoir monitoring, improving artificial lift performance and allow creating Pigging lift "New artificial lift concept". U shaped well accompanied with a new pigging artificial lift method study shows the following progress: 1. Additional down hole barrier from the deepest point and additional open side keep the well under control more over minimize the existing well control killing procedures with low cost and risk in addition to discarding the CT operations for killing or prepare the well for W/O. 2. Decreasing stimulation pressures needs (double injection rates) and overcome the existing accessibility challenges 3. Allowing pull heading stimulation w/less displacement time and high rate and chimerical batch pumping from one side to another increase well life and eliminate PKRs risk as chimerical batches will be pigger, easier and faster. 4. Additional down hole monitoring system allowing uniform stimulation and discarding the CT operations for well stimulation and cleaning, 5. Avoiding post stimulation damage throughout fast clean-up 6. Ability to stimulate from one side with artificial lift from other side Avoiding the corrosion and erosion by faster operations 7. Allow faster plug and perf. multistage fracturing technology and overcome the unconventional well fracturing which required rate and pressure 8. Eliminate rig usage to pull the frac string to run completions 9. Step change for reservoir mentoring without S/D and real-time Logging, Sampling The deployment of U Shaped Well allows new artificial lift concept (Pigging lift) to apply. This new approach led to improved wells performance also raising efficiency of the use of the existing resources besides saving time and in return cost. This approach helps in improving well utilization and efficiency levels.

An Innovative Approach to Install Production String with ESP to Avoid Productivity Impairment in Multistage Fractured Horizontal Well

Objectives/Scope Generally, tight reservoirs require hydraulic fracturing to enhance and sustain hydrocarbon production. However, fracturing requires frac string with bigger Internal Diameter (ID) to minimize frictional losses during hydraulic fracturing operation. This string ID may not be suitable to provide optimum Vertical Lift Performance (VLP) during production phase, particularly in oil wells. Therefore, it is required to replace the frac string with production string of smaller ID. Occasionally, artificial lift also becomes essential to overcome VLP issues in future due to progressive water production and declining reservoir pressure. Methods, Procedures, Process Completion replacement often causes reservoir damage due to killing operation, which can be removed in conventional carbonate reservoirs by matrix stimulation. However, formation damage removal is difficult in hydraulically fractured tight carbonate and sandstone reservoirs. Preventive measures become essential to avoid productivity impairment particularly in hydraulically fractured reservoirs. Different preventative options are proposed and reviewed to isolate reservoir with their advantages and disadvantages. After comprehensive studies and risk assessments, an innovative modification in the completion plan was introduced and finalized. This plan includes production string with Electrical Submersible Pump (ESP) to improve VLP. This completion provides full accessibility intervention job, which may be required for reservoir monitoring and surveillance in future. Results, Observations, Conclusions A comprehensive production test is performed to evaluate and compare the testing results of pre and post workover. Testing results show there is no impairment in productivity of the reservoir, which is avoided in workover process by isolating reservoir section. This paper summarizes the completion design process, selection criteria, challenges, and lessons learnt during design and execution phases. This technique will provide the guidelines for installation of the Production string/ESP in hydraulically fractured reservoir without productivity impairment. Novel/Additive Information With modified design, the reservoir is isolated from wellbore and completion with ESP is run successfully without killing reservoir section. Underbalance conditions are achieved prior to establishing communication between reservoir and wellbore.