bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic Lithology Classification of Cuttings with Deep Learning
Authors: Nanjo Takashi , Ebitani Akira , Ishikawa Kazuaki , Konishi Yusaku , Miyoshi Keisuke , Shulakova Valeriya , Beloborodov Roman , Kempton Richard , Delle Piane Claudio , Benedict Clennell Michael , Sagotra Arun , Pervukhina Marina , Mizutani Yuta , Harada Takuya
Published: February 2023

Describing cuttings is routine work for wellsite geologists on a drill rig. The time-consuming nature of this analysis and the lack of consistency of the results between different interpreters are the two major concerns for this task. Wellsite geologists spend approximately 70% of their time on cuttings descriptions. In addition, 2 to 3 wellsite geologists are generally assigned to a drilling campaign, and they are replaced at the end of a shift. ML/AI techniques have the potential to solve these issues because of their advantages in prediction speed, objectivity, and consistency. The authors’ aim is to automate the task of cuttings descriptions with ML/AI techniques.

We are targeting four lithologies, namely sandstone, mudstone, volcanic (volcanic rocks), and carbonate (carbonate rocks). The cuttings were collected from six wells in the Browse Basin (Australia). Of these four lithologies, a total of 1978 cuttings images were taken under a stereomicroscope.

We chose a semantic segmentation technique using Convolutional Neural Network (CNN) algorithms to perform the image classification task. The images were labelled using the open-source annotation software. This annotated data were used for the network training. The labelled images were split into training, validation, and test sets.

The accuracy of the trained model was evaluated using the intersection-over-union metric (IOU). The mean IOU of the final model on the validation dataset was 82.3%. Prediction results on the cuttings that are represented by single lithologies are qualitatively very accurate. On the other hand, the prediction for the non-typical lithology (e.g., siltstone, dark-colored volcanic rocks, mixed lithology samples) has room for improvement. The fragments with similar textures (e.g., dark colored volcanic and dark mudstone) are complex for the CNN to identify. The final goal of our project is not only the lithology identification but also the quantitative estimation of lithology abundances in the cuttings. Additional model improvements, such as hyperparameter optimization and significantly more training data, are required to accomplish this task successfully.

The trained model for cuttings description has the potential to realize quantitative and high-speed cuttings description. Well-trained AI/ML models have the potential to assist well site geologists by automating the cuttings description process simplifying, speeding up and improving the consistency on the rig floor.
Oscillation Fishing System: A Novel Approach to Improve the Chances of Freeing Shallow Mechanical Stuck Pipe
Authors: Han Kyungnam , Alharbi Sultan , Albaqshi Ahmed , Eltoum Ahmed
Published: February 2023

One of the most common and costly situations in drilling operations is stuck pipe recovery, as it results in significant non-productive time (NPT). Stuck pipe is often freed by applying axial jarring forces to the string to overcome the sticking force. However, becoming stuck at a shallow depth often results in insufficient pipe stretch in the string to generate enough energy to free the stuck pipe using a jar.

In cases where it is not applicable to use a jar, the use of the Oscillation Fishing System (OFS) is a more effective technique and an optimal solution to free the stuck pipe. Using the OFS to free stuck pipe encompasses generating continuous oscillatory axial motion. Pressure pulsations generated within the tool are converted to steady axial oscillations using the springs in the tool. This continuous motion produces axial forces at high frequencies, which translates to continuous energy applied to the stuck pipe.

The OFS is used in different fishing applications, such as vertical and directional well profiles. The technology is used to free stuck pipes in cased and open holes. Depending on the stuck situation, the OFS is either placed at the surface or downhole with conventional bottom hole assemblies (BHA). In the subject applications, the OFS was run at the surface to free both motor and slick rotary BHAs in large hole sizes, 22 in. and 16 in., in different scenarios.

This paper will analyze four examples where the OFS was used in a similar application. In all these examples, conventional stroking tools (i.e., fishing jar) were not part of the system and jars were not used to avoid the potential hazards of impact forces affecting the rig floor. Moreover, activating jars at shallower depths is ineffective as it requires a longer length of pipe to generate enough energy to free the stuck fish. The OFS was used after unsuccessful attempts to pull and recover the string. When the OFS was activated at the surface, producing continuous axial movement, it successfully freed the stuck fish.

A new application of the OFS in fishing operations was introduced by using it in the surface sections. Not only did the OFS eliminate the extra steps required to get closer to the stuck point, but also it saved rig time and drillstring components and prevented the need for sidetracking. This paper discusses the use of the OFS at the surface in three examples, including an analysis of the performance to free the stuck string.
Unlocking Gas Production Potential for Ultra-High H2S Reservoirs: Closed-Loop Testing Avoids Flaring and Toxic Gas Release
Authors: Alaithan Monaf S. , Leal Jauregui Jairo Alonso , Al-Hazmi Waleed Ahmed , Sarac Sukru
Published: February 2023

Flowback operation of ultra-high H2S gas well is a challenging scenario due to complex environmental considerations, equipment limitations and limitations on surface flow management with unstable well conditions. This paper will present an application where flaring impacts were significantly minimized and no H2S gas was released to the atmosphere, unlocking the production potential of high-H2S formations.

Then, a new Technology concept is being developed. A brand new Closed-Loop Testing package has been implemented to overcome the flowback limitations with high H2S concentration and minimize flaring during well clean-up. Simulation results of expected wellbore dynamics during well start-up were studied to optimize flowback package fluid handling capacity and perform safe operating conditions. New inline measurement devices were used for H2S, CO2 and inline density measurement were key on providing in-line well monitoring parameters as well as better decision points and control in key elements and including; new control valve metallurgy, new metal-meat seals, new PRV design/metallurgies, new EE-NL pipeline, new approach in low pressure systems, pressurized storage vessels both condensate and water, as well as avoid any human exposure for critical procedure including water, PVT sampling and gas metering validations. This new approach allows to complete this task without releasing toxic gases to the atmosphere. Selected equipment also allowed continuous flow to clean-up the wellbore and safely transfer the fluids to the production line, minimizing flaring while avoiding any environmental impact.

Wellbore behavior during well kick-off was as expected based on the transient wellbore and reservoir simulations, which helped achieve a continuous flow to safely flow the wellbore and handle the produced fluids. The selected closed-loop testing set-up in addition to continuous well monitoring with new inline measurement devices allowed remarkable flow management optimization. This reduced CO2 and toxic gas emissions, minimizing environmental impact. Toxic gas release in the flowback area was also avoided by eliminating manual measurements with the closed-loop testing package. The wellbore was cleaned-up to achieve the production tie-in criteria. This implementation acts as a proof of concept to flowback high-H2S wells.

This paper presents the new testing equipment and practices to enable safe flowback in high and ultra-high H2S conditions. The example explained in this paper is the first post-stimulation wellbore flowback in Saudi Arabia, including ultra-high H2S conditions being achieve by a new closed-loop well-testing package.
Vertical Seismic Profile Modelling and Applications for a Deviated Well to Improve Surface Seismic Interpretation
Authors: Negenman Brendon , C. A. Razak M Amin Nizar , Yusof Ahmad Izzuddin
Published: February 2023

Vertical seismic profile (VSP) data is a powerful calibration tool that helps to link the time (surface seismic) & depth domains (well logs). Conventional rig source VSP data is not recommended to be used in a highly deviated well for seismic calibration. Excessive ray bending from the source-receiver offset will cause errors in the vertical time calculations, and this data will not be reliable to calibrate the surface seismic. This paper will discuss a case-study for a highly deviated offshore well using a vertical incident VSP (VIVSP) source geometry.

A VIVSP is a unique type of geometry that places the source above the receiver array. This is usually done using a supply vessel for an offshore environment. Placing the air gun source above the receiver ensures vertical raypaths, and this gives the most accurate TWT result. Planning is crucial for this type of VSP to calculate the number of receiver arrays & source positions. 2D ray trace modelling using the surface seismic interval velocity & VIVSP geometry was used to verify the data would be within tolerance for vertical raypaths, and to optimize the acquisition time.

VSP data was acquired using the optimized vertical incidence geometry. Data quality was excellent which gave a reliable time-depth profile for most of the well interval. VSP data was processed to corridor stack. and CDP transform was used to create an image below the well trajectory. This data was used to calibrate seismic velocity during seismic processing, as well to tie surface seismic to well.
Application of Biosteered Underbalanced Coiled Tubing Drilling in Optimizing Production
Authors: Alshuhail Faisal , Alsaad Mohammed , Alqahtani Mahboob
Published: February 2023

Executive Summary

The objective of this study is to compare the performances of Underbalanced Coiled Tubing Drilling (UBCTD) versus conventional drilling with stimulation in a Permian carbonate target within a field in Saudi Arabia. The focus of this study is to ultimately investigate the effectiveness of biosteering in UBCTD compared to geosteering and subsequent stimulation in conventional drilling of vertical and horizontal wells within the same target.

Biosteering is an application of biostratigraphy used to navigate and maintain well paths within the desired zone. This technique has been employed successfully in UBCTD wells in the Middle East. Biosteerers utilize the characteristic distribution of microfossil assemblages obtained from cuttings samples with the identification of biozones based on existing schemes. The most effective way to geosteer these well is to use this technique in conjunction with lithology descriptions, GR log trends, visible porosity and drilling parameters. UBCTD wells are not stimulated as there is minimal induced formation damage during drilling operations. Geosteering utilizes logging while drilling (LWD) in horizontal wells for lateral placement and to determine perforation intervals. Conventional wells in this study are all stimulated, employing multistage acid fracturing techniques. The dataset in this study comprises 50 wells, all of which are compared by normalized post-completion performance.

Post-completion performance from the 50 well dataset was normalized to achieve a representative comparison. UBCTD biosteered wells show indicative superiority when compared to horizontal and vertical conventionally drilled and stimulated wells. In addition to the minimal formation damage in underbalanced wells, footage in the target is higher in biosteered UBCTD wells compared to geosteering. This is due to several reason with the main reason being is the ability of UBCTD to drill multiple laterals in each well, thus maximizing target contact. A detailed look into two wells targeting the same formation and field proved effective UBCTD utilization, yielding a production increase of several orders of magnitude.

Despite these results, the normalized production performance may not account for significant LWD merits. In terms of steering, UBCTD slim-hole nature limits applications of available LWD technologies that provide essential information for reservoir characterization and development plans.
Online Measurement and Analysis Technology of Oil & Gas Multiphase Flow by Magnetic Resonance
Authors: Deng Feng , Chen Shiwen , Chen Guanhong , Wang Mengying , Liu Chao
Published: February 2023

In the petroleum industry, there is a huge demand for oil & gas multiphase flow metering and fluid property analysis. In addition to common production metering and economic transfer, it also includes downhole metering, drilling and completion fluid testing, oil testing, gas testing, storage and transportation testing, etc. This is an important parameter that needs to be mastered to provide flow guarantee for oil and gas production and transportation. So far, the multi-phase flow measurement methods are usually with low-efficiency, low-accuracy, high-costs and delay-delivery, and hard to reflect the real instantaneous fluid producing properties at wellheads or pipelines. Magnetic resonance (MR) technology is considered to be the most promising multiphase flow measurement technology, but at present it also needs to solve technical problems such as low measurement frequency, static measurement of phase holdup, poor environmental adaptability of the instrument, and high cost.

Based on the previous work, this paper addresses the problem of low measurement frequency and inability to flow measurement with traditional low-field MR measurement methods, and proposes a dual-antenna measurement method, which increases the measurement frequency from 0.2Hz to 1Hz, and realizes online measurement of phase contents. A novel integrated probe structure is proposed, which widens the working temperature from -30 to 80 °C, increases the pressure range to 40 MPa, improves the anti-electromagnetic interference ability, and increases the measurement range to 600,000 cubic meters/day for the gas phase, while reducing the cost.

The instrument has carried out various tests in 50+ wells in China, and the liquid phase measurement error is less than 5%, and the gas phase measurement error is less than 10%. This progress further helps to apply the NMR technology to oil & gas production industry, to realize green, efficient, online, low cost, full range multi-phase fluid measurements. The on-site fluid properties analysis capability moved the laboratory test to the oil & gas fields, improved efficiency, accuracy and reduce costs.

As a flowmeter, the device reduces the amount of measuring equipment needed and manage wells more efficiently, as a ‘fluid analysis laboratory’, can provide the first-hand information on the oil/gas properties.
Well Optimisation Technique with Backward Elimination Process for Greenfield Gas Development
Authors: Vardcharragosad Pichit , Doungprasertsuk Chonlada , Srisuriyon Jantakan , Hamdan Mohamad Kamal
Published: February 2023

The well optimization technique with backward elimination aims to determine the optimum number of wells and their locations that can maximise project value and its recoverable resources, through repeated ranking of candidate wells and eliminating the poorest performer. For a greenfield development, subsurface uncertainties are typically still very large due to limited data from exploration and appraisal wells. This study outlines our approach to perform well optimization with these governing uncertainties in order to support the decision-making process.

First, multiple realizations of reservoir models are constructed to represent range of possible outcomes by sampling different values from uncertainty parameters. Backward elimination for well optimization is then performed on those realizations. Wells can be ranked based on means and standard deviations of their performance, and the lowest rank candidate is eliminated from the process one at a time. At this point, project economic and resources are evaluated to find optimum set of wells for field development. Furthermore, well performance data from multiple realization models are carefully analyzed to define key subsurface uncertainties that need to be managed.

Solution from this backward elimination with subsurface uncertainty workflow can maximize project valuation because it balances the risk of overspending to drill sub-optimum wells in some realizations with the risk of losing sell opportunity due to insufficient field deliverability in the other realizations. Development decision will be more robust because it is based on the optimum configuration that is applicable irrespective of the unknown uncertain quantities. Moreover, detailed analysis on well performance data allows us to better understand the risk associated with our planned wells so that appropriate de-risking plan can be developed and combined into development strategy.

The backward elimination process is straightforward to implement and normally does not require very high computational expense. Thus, it is suitable to be used with uncertainty workflow with multiple realizations of reservoir models, which will increase computational requirement by multiple times. Other commonly used techniques for well optimization such as a Genetic Algorithm (GA) or an Evolutionary Algorithm (EA) are computational expensive by themselves already; and they will require even more runtime when using them with this uncertainty workflow.

This paper extends backward elimination approach for well optimization to be used with uncertainty workflow. The overall uncertainty analysis workflow is discussed and provided, with key steps detailing the approach taken. Project valuation and recoverable resources can be further optimized with this new approach, and ultimately can guide the decision making in field development.
Extended Abstract: Complex Offshore Well Intervention Now Possible by Using Thru-Tubing Bridge Plug to Produce By-Pass Zone and Isolate Lower Production Zone
Authors: Eyuboglu Sami , Siregar Erlangga , Andhika Banu , Murvianto Febrian , Yuliarosa Zandra , Siahaan Patria
Published: February 2023

Isolating lower production zone (water shut-off) and finding new perforation intervals from another reservoir zone is a typical well intervention application in mature fields. In normal conditions, legacy permanent barriers (Through Tubing Bridge Plugs -TTBP) have been used in those applications very successfully. However, challenges are posed by, well bore restrictions (passing smaller OD restrictions), rig height, reliability and setting validations with legacy tools in harsh environments and well conditions. This paper discusses the challenges during offshore well intervention operation in Indonesia due to the limited space for rig-up, limited crane lifting capability, and un-manned well platform with only daylight operation and the solutions for these challenges with new slim-sized TTBP technology and the slim-sized Pulsed Neutron tool.

Critical success factors of this operation included providing valid gas saturation data by using a 1 11/16" Pulsed Neutron tool (TMD3D) to determine the remaining gas in producing interval and any bypassed opportunities; establishing enough force by using a slim size electromechanical setting tool (DPU) to set the 1 11/16" TTBP at the desired depth and establishing a mechanical barrier which can hold up to 1200 psi differential pressure until a cement cap can be established; and running a perforation simulation to select the right gun to create an effective perforation tunnel between the wellbore and the formation for optimized gas production from the bypass zone.

Despite all the challenges, a good mechanical barrier was established to isolate the lower water production zone and successfully determine gas saturation in bypassed reservoirs by using the Pulsed Neutron data. Perforation intervals were selected with the pulsed neutron analysis. After perforation, significant gas production was established which was 50% higher than predicted. New slim-sized technology tools resulted in flawless job execution with their high reliability and cost-effective solutions without any service quality issues. In addition to increased gas production, efficient operation resulted by completing the job one week earlier than scheduled, which provided extra cost savings. This case study identified the challenges in complex well intervention operations and provides a valuable water shut off solution by using new 1 11/16" TTBP and 1 11/16" DPU technology. The solution has proven to provide tremendous cost saving for production enhancement activity.
Successful Development of the Deepest Oligocene Syn-Rift Sediment in the Malaysia-Thailand Joint Development Area: Is the Deeper Zone Our Future?
Authors: Setiawan Avidianto Suryo , Simatupang Martin Hendra , Rachmadi Arif , Apiwathanasorn Sippakorn , Moh. Said Samsul Bari
Published: February 2023

Field X, located in the offshore Malaysia-Thailand Joint Development Area (MTJDA), comprises multiple stack gas reservoirs with a combination of trap styles. This paper highlights the challenges and lessons learned in successfully developing the deepest Oligocene syn-rift sediment in the MTJDA, which was initially discovered by the one appraisal well drilled in 2010. A further comprehensive evaluation was performed to justify the deepening of development drilling in 2019 (as appraisal cum to development) and 2021-2022 (as infill wells) with promising results.

The discovery of hydrocarbon resources in the deepest Oligocene syn-rift sediment at MTJDA was part of an appraisal program by deepening the development well. The two wells discovered and proved the presence of multi-stack gas sands in this deepest section (3800-4000 mTVDSS). The clastic sediment deposits in a fluvio-deltaic system. The reservoir properties of this syn-rift sediment are better than the early post-rift sediment (early Miocene). The production test confirmed the initial gas flow rate of about 15 MMscfd. A comprehensive analysis was performed to evaluate a sizeable volume before more development wells were proposed for this deepest sediment.

The initial understanding of Late Oligocene syn-rift sediment was very minimal at the beginning of the project. One of the neighbouring well information suggests lacustrine delta environments based on core data. However, a fair-quality seismic amplitude shows a broader channel belt (over 3km width) which usually exists in the braided stream. In view of the two appraisals cum to development wells’ successful discovery, more than five wells were proposed to penetrate this zone as a deepening target from the existing discovered zone. The fit for purpose well designed with a monobore concept, was selected. Upon completing the development drilling with denser well spacing, it suggests the discontinuity of blocky sand presence with multiple fluid contact (stratigraphic compartmentalization), which is usually found in narrower channel reservoirs at the deltaic system rather than the braided stream. The good reservoir properties observe from the open hole log, formation tester, and production test. The success story of these wells opens future opportunities to plan more deep well to develop Oligocene sediment, which prove to be a good hydrocarbon producer.

This paper updates the previous understanding of geology, such as the depositional environment, and the understanding of reservoir productivity of the Oligocene sediment in MTJDA. It also proved sizable reservoir quality with extensive lateral presence and good productivity. Hence, the company foresee a promising future from this deep reservoir to prolong its long-term development plan.
Numerical Simulation for Compaction and Subsidence During Production Period for a Large Carbonate Gas Field
Authors: Kusolsong Skaow , Adisornsupawat Kanitthorn , Vardcharragosad Pichit
Published: February 2023

Many gas fields were discovered in carbonate build-ups located in Sarawak, Malaysia. One of the most challenges and well-known issue to operate these fields is the reservoir compaction and surface subsidence. In the new discovered field, which was recently discovered in 2019, the data related to stress magnitude and mechanical rock properties is very limited. The available cores were used to perform the essential rock mechanics laboratory test. The coupling between reservoir dynamic simulation and mechanical earth model (MEM) was selected as an approach to predict the episodic compaction and subsidence through the field life. The 1D mechanical modeling was then performed, calibrated with rock mechanics laboratory test, and used as the key input in 3D mechanical earth modeling. The coupling steps between dynamic and 3D-MEM were selected throughout the production lifetime when the pressure depletion is significant compared to the previous coupling step. Based on the literature review, the reservoir compaction and subsidence occur in this region was caused not only from the reversible elastic deformation but also from the effect of pore collapse in some classes of the limestone. This pore collapse during pore pressure depletion and increase in effective stress tends to have more impact to the subsidence than the normal elastic deformation. This behavior was also captured and incorporated using critical state criterion. The results of the coupling will strongly have the impact on how the platform will be designed to account for potential subsidence throughout 20 years of production. Due to the limitation of input parameters in the 3D-MEM, the sensitivity analysis was performed to assess the impact of each mechanical properties on the magnitude of the reservoir compaction and subsidence. The use of ready coupled 3D-MEM can also be further extended to other applications such as wellbore integrity, wellbore stability analysis, and mud weight optimization at any given period of time. Moreover, the impact of the compaction and subsidence in this study could leads to better planning in data acquisition such as rock mechanics data, laboratory test, and logging acquisition program to narrow down the uncertainty of the subsidence analysis and other geomechanical applications.
Unlocking the Potential of Unlabeled Data in Building Deep Learning Model for Dynamometer Cards Classification by Using Self-Supervised Learning
Authors: Wibawa Ramdhan , Rosyadi Rosyadi , Nancy Maulirany , Irfani Hasya Fulki Raden
Published: February 2023

Dynamometer card is one of the vital surveillances for Sucker Rod Pump (SRP) performance monitoring in Duri field. Even though the field produces a massive number of cards, they come with no label or interpretation about the pump conditions based on the card shape. Self-supervised learning (SSL) consists of a pretext task that trains feature extractors by using unlabeled data as opposed to supervised learning, that requires a lot of effort in labeling data which is time consuming and costly. This paper evaluates the performance of a feature extractor, Alexnet, that is trained by using several pretext task techniques. This study used around 660,000 unlabeled cards while a small amount of labeled data was used for evaluation purposes using linear evaluation protocol. The result showed that the trained Alexnet using Pretext-Invariant Representation Learning (PIRL) with jigsaw has better performance by 6% compared to the pre-trained ImageNet model. Further fine-tuning process by using labeled data could achieve 93% accuracy. The model was also tested using fresh data and the result was compared to the expert's interpretation. This approach can potentially add more types of rod pump problems to detect in the Duri field with considerable precision. In addition, the new approach could improve the current method of detecting more SRP with valve leaking problems.
Taking Petrophysics to New Horizons – Far Field Saturation and Lithology in Clastic Reservoirs
Authors: Hermawan Manuaba Ida Bagus Gede , Ghanim Rayan Adil , Bikchandaev Eduard , Taher Ahmed
Published: February 2023

Conventional logging-while-drilling tools acquire measurements close to the wellbore. Recent development of deep and ultra-deep resistivity technology has enabled measurements more than 100 ft from the wellbore. Far-field petrophysics in simple carbonate lithology is possible since saturation is dependent on resistivity and porosity. Hence, combining deep and ultra-deep resistivity measurements with data from offset wells can provide reasonable saturation mapping. However, in clastics the evaluation is more complicated since resistivity is more dependent on lithology.

In most cases, the main challenge in carbonates is permeability identification. Far-field carbonate petrophysics can be derived from mapped resistivity utilizing deep or ultra-deep resistivity and offset logs. Evaluation of far-field petrophysics away from the wellbore in clastics is more complicated as it requires lithology identification to be incorporated into the petrophysical model. A workflow has been developed integrating near-wellbore measurements with ultra-deep resistivity and anisotropy derived from 3D inversion. The workflow provides a qualitative indication of the lithology, allowing saturation in porous sand to be derived based on inverted resistivity.

An innovative workflow has been developed based on the available data and combining multiple sources of data from near wellbore, offset logs to inverted resistivity data. 3D inversion plays a critical role in this workflow as it provides a lithology indication far away from the wellbore, differentiating between shale and sand. The identification of shale members at a distance also provides critical information for models of reservoir connectivity and potential barriers to water influx. The combination of far-field petrophysics with lithology gives better evaluation on a reservoir scale for critical decisions in terms of completion and reservoir performance.

The new workflow has been successfully tested on several wells and different reservoirs. The workflow has been used for far field petrophysics and saturation mapping based on real-time logging-while-drilling (LWD) data and offset data analysis combining shallow and deep measurements with the 3D inversion from ultra-deep resistivity. There are several benefits from this innovative workflow, including optimizing well placement, improving understanding of fluid distribution, and optimizing completions design and reservoir management strategies.
Resolving Uncertainty in Oil Quality and Extension of Field Producible Area Using Latest LWD NMR Technology
Authors: Al-Fawwaz Abdullah A. , Usman Anes Y. , Najem Mohammad M. , Aboudi Abdulrahman , Al-Otaibi Fahad , Van Steene Marie , Dolan James
Published: February 2023

This paper describes how the uncertainty in oil quality in an offshore carbonate reservoir was resolved using the latest slim logging-while-drilling (LWD) nuclear magnetic resonance (NMR) tool. This tool was included in the bottomhole assembly (BHA) during drilling of the sidetrack well with the objective of confirming the presence of immovable heavy-oil/tar mat below the light/heavy-oil contact (LHOC). However, the tool showed that the reality was different from the expectations as movable/light hydrocarbon was confirmed below LHOC thereby leading to an extension of the field producible area.

The NMR interpretation methodology followed two scenarios based on an offset well with a rich NMR dataset. In the first scenario, because of the absence of porosity deficit and low apparent bound fluid volume, no heavy oil was identified, and the tool provided permeability and irreducible water saturation. In the second scenario, heavy oil was identified primarily from the presence of high apparent bound fluid and secondarily by a porosity deficit, and oil viscosity was computed.

The high-angle well intersected the same carbonate reservoir layer multiple times. The NMR measurement showed that Zones A–1, A–3, and B contained light oil, while the expectation for Zone B was to contain a heavy oil layer below the LHOC. The NMR identified heavier oil in each crossing of Zone A–2. An oil viscosity gradient was observed on both crossings of the reservoir layers. The reservoir was otherwise at irreducible water saturation in the subsequent interceptions, and the heavy oil or tar were not identified again. All the observations from the tool were supported by related observations from the mud logging gases. The first application of this service in this field was a success. The NMR provided unique fluid typing information, confirming that most reservoir sections contained light oil and quantified the heavy oil viscosity variations along the reservoir layer, which could not be quantified from the density, neutron, or resistivity measurements.

Finally, the NMR measurement showed that the reality of heavy oil distribution in this part of the reservoir was quite different from what was expected (i.e. the presence of immobile heavy oil below the LHOC) based on the reservoir model, enabling the prospect of light oil production from this part of the reservoir.
Research and Practice of Steam Huff and Puff Depressurization and Increase Injection Volume Technology for the First Offshore Super Heavy Oil Reservoir in China
Authors: Wang Hongyu , Wang Qiuxia , Han Xiaodong , Zhang Hongwen , Liu Hao , Wang Cheng , Zhang Hua , Wang Zhiyuan , Dou Peng
Published: February 2023

The surface crude oil viscosity of the first ultra-heavy oil field in Bohai Oilfield is more than 50,00mpa·s, which is unable to be developed under the condition of original formation temperature and requires steam stimulation. In the first period of steam huff and puff well, due to sufficient formation energy, steam injection pressure is high in the process of steam injection. The measures to reduce the steam injection speed are mostly adopted in the field, but it will lead to the problem of large wellbore heat loss and affect the steam stimulation heat injection effect. In this paper, based on the oil characteristics of the first ultra-heavy oil field in Bohai Oilfield, the evaluation of oil soluble surfactant was carried out, and the experimental study of pre-injection of oil soluble surfactant to reduce steam injection pressure was carried out. It has been successfully applied in the development of the first ultra-heavy oil in Bohai oilfield. The results show that the oil soluble surfactant with asphaltene dispersibility has better temperature resistance and viscosity reduction effect, and the viscosity reduction effect is more than 95% before and after aging. Laboratory experiments show that the oil soluble surfactant can reduce the steam displacement resistance of the displacement front and the affected area. When the injection amount of oil soluble surfactant is 0.2PV, the maximum steam injection pressure can be reduced by 22.9% and the steady steam injection pressure by 10.8%. The design treatment radius of oil soluble surfactant is 0.15m, and the field test shows that the steam injection pressure decreases by 1.1MPa during steam injection.

After adopting the depressurization and increase injection volume technology, the field injection pressure is effectively reduced, the steam injection effect of ultra-heavy oil is guaranteed, and the technical guarantee for the subsequent development, promotion and application of ultra-heavy oil is provided.
Increasing Run Life by Using Multiple Preventive Downhole Pump (MPDT) to Overcome Gas Interference and Sand Problem on Sucker Rod Pump Well
Authors: Suryantoro Rahma Wisnu , Oktoviyanto Yusuf , Dewanata Dionisius , Arif Luqman , Akbar Despredi
Published: February 2023

Rantau is a mature oil field located in Aceh, Indonesia, which has been producing oil since 1928 and reached the peak production in 1970s. The reservoir in Rantau field is already depleted so it needs artificial lift to produce the oil. About 71% of artificial used in Rantau are sucker rod pump (SRP), 26% are electric submersible pump (ESP), and others remaining are gas lift. To maintain production with a high decline rate efficiently gets more challenging with the downhole problem, especially gas interference dan sand problem.

In 2020, 78% of well services came from artificial lift wells with sucker rod pumps. The data said that sand problem with gas interference became dominant causes in 74% of the cases. To solve those issues with the limitation of cost and maximizing the effect, modification of tubing pump accessories was chosen. Multiple Preventive Downhole Pump (MPDT) is a modified tubing pump accessory that has seven stages to minimize sand production and separate the associate gas while the fluid was pumping into the surface.

The sand separation was effective enough to prevent a huge amount of sand and gas from the reservoir infiltrating the pump assembly, so the sand could not produce to the surface or blocking the standing or traveling valve and gas pound could not occur. The four wells installed with MPDT could exceed their previous run life more than five times. This brings impact on the less well service activity in those wells and for Rantau field in general. During the observation, the fluid sample taken from the wellhead showed no sand to a small amount of sand produced, as the wells produced a small amount to no sand at all we could optimize its parameter to achieve more oil, while when the well produced a huge amount of sand, its parameter could not be optimized or increased which could lead to more sand produced to the surface. In conclusion, well that installed with MPDT become more efficient contributed by longer run life which led to less well service work and increased oil production where its parameter could be optimized.

MPDT could prevent reservoir sand getting into the tubing pump, as well as the gas. It is a practical solution for mature oil fields that encounter sand problems as a common challenge in producing oil.
Apply Cost Effective Multiple Cementing Technologies to Sidetrack in Air Drilling Environment in Chiya Khere Field
Authors: Hasan Hawraz , Ibrahim Krewa , Majeed Ali , Shafqat Ali , Abdulfattah Suwar , Ibrahim Mohammed , Qader Rebeen
Published: February 2023

Chiya Khere field development plan is to drill a lateral hole from existing pilot holes. While in the drilling phase, severe losses were hindering the drilling plans due to lack of effective solutions to sidetrack in air drilling environment. Historically, losses circulation pills were never effective to cure the losses in highly fractured zones, the drilled wells in this field were abandoned using mechanical barriers (Bridge plugs) to facilitate the lateral plan, which was increasing the field development time and cost. Also, due to difficulties to obtain open-hole mechanical bridge plugs the well project duration was extended significantly, furthermore, isolating the loss zone using mechanical tools is the least preferred primarily due to availability and then setting failures in the big hole. In this paper, a newer approach will be presented to demonstrate the specialized technique to cure total losses which resulted in a significant reduction in the operational cost to drill these laterals in Chiya Khere field without changing the casing designs or postponing the project due to no viable solution and explains detailed techniques to overcome the challenges. Some techniques to combat severe losses are pumping loss circulation pills, drilling under balance, and pumping cement plugs. A new and unique loss control strategy was introduced in one of the recently drilled well in this field, in which two pills of solid free spacer separated by a fiber carrier fluid were pumped for instant bridging and viscosifying at the downhole were injected into the losses zone to create a temporary lock-up prior to pumping a rapid gelled cement plug for permanent isolation, once the losses been controlled a firm base cement plug was placed to spot a high compressive strength cement plug (kickoff cement plug), Applied proposed techniques led to having successful results in which rapid gelled cement headed by losses circulation material (LCM) solution combination cured the losses and successfully isolated the bottom of the hole which facilitated to placement a basement plug then kick off cement plug, and tag at the designed top of cement (TOC) to drill the lateral to the new planned trajectory.
Data-Driven Performance Analysis for Candidate Recognition: A Case Study in a Giant Heterogeneous Carbonate Reservoir
Authors: Sun Liang , Wu Bohong , Gao Yan , Li Yong , Jiao Yuwei , Wei Chenji , Shi Shuzhe
Published: February 2023

In the whole lifecycle of reservoir development, periodic intervention in wells is the daily work of reservoir management, which is essential to production maintenance and workover activity. The identification of actionable plan at well-by-well level is time consuming and inefficient, especially for reservoirs with a considerable amount of wells. Over-reliance on engineer experience also increase uncertainties over reliable plan. The workflow for candidate screening provides a systematic and efficient approach to dealing with this issue.

Prior to commencing the process, reservoir static model and dynamic model were updated to meet recent reservoir performance. The first step was to identify potential wells in two ways, including the typical diagram indicating the relationship between production performance and reservoir properties, and the modified heterogeneity index method introduced by Del Castillo et al. After completing candidate recognition, diagnostic analysis was conducted to determine root causes through dynamic analysis of injection/production performance at well/pattern level. Finally, comprehensive evaluation and forecast for workover activities were carried out in terms of technical and economic aspects, which will facilitate appropriate decision making.

This workflow has successfully been applied to a giant heterogeneous carbonate reservoir with gas cap. The identified candidates can be categorized into four types. The whole/partial gas cusping wells with a sharp/gradual increasing trend in gas-oil ratio (GOR) are influenced by gas cap. The gas channeling wells with uneven sweep efficiency are attributed to the injected gas overriding in heterogeneous reservoir. The water cusping wells with medium water cut are influenced by bottom aquifer. Accordingly, an integrated optimization plan is proposed to mitigate the outlined risks. The recompletion strategy with Autonomous Inflow Control Device (AICD) and sliding sleeves is recommended for gas/water cusping wells, and results are phenomenal in terms of segmented isolation of high GOR/water cut intervals and delaying gas/water breakthrough. The converting from gas injection to tapered water-alternating-gas (TWAG) through increasing the ratio of water-to-gas in a step wise process has been implemented for gas channeling wells, and an improved conformance is observed. The TWAG project appears to be promising because of high gas/water utilization efficiency and reduced gas cost.

This methodological approach provides a generic workflow for conducting an integrated analysis of workover candidates screening and plan making. Reservoir performance will be monitored and maintained in order to ensure efficient reservoir management practice.
Incidência da polifarmácia em idosos com doenças crônicas
Authors: Lemos Lara Souza , Suarta Made William , Huszcz Gabriel Barbosa , Rodrigues Camila Gouvêa , Rocha Eduardo Quaresma , Silva Beatriz Moreira , Oliveira Marcus Vinicius de
Published: February 2023

Objetivo: Descrever a relação entre polifarmácia e doenças crônicas em indivíduos com mais de 64 anos. Métodos: Analisar indivíduos acima de 64 anos, por intermédio de formulários pré-existentes em uma instituição de ensino superior, foram elegidos 146 formulários correspondentes aos objetivos da pesquisa. Resultados: Foram revisados 480 prontuários, sendo que 146 enquadram-se na elegibilidade da pesquisa, isto é, idosos acima de 64 anos, sendo a maior parte da amostra do sexo feminino (64,4%). Essa análise foi feita por meio da extração de dados de prontuários entre 2015 e 2020, uma vez que no período de pandemia a Policlínica não se manteve aberta para atendimentos. A média de idade foi de 71,4 anos com um desvio padrão de 6,6. Dos 146 selecionados, 124 (84,9%) eram portadores de doenças crônicas, 76 (52%) estavam em polimedicação, sendo, destes, 68 (89,4%) pacientes com doenças crônicas, e dentre os 70 (48%) que não estavam em polimedicação, 56 (80%) pacientes tinham doenças crônicas. Conclusão: A relação do uso da polifarmácia com as doenças crônicas está dentro do padrão encontrado. A prevalência de mulheres que usam a polifarmácia foi semelhante aos achados nos outros estudos selecionados. Todos os selecionados tinham como principais doenças a hipertensão arterial, diabetes mellitus, obesidade e/ou tabagismo.
Sakralitas Pernikahan dan Kedewasaan Diri dalam Analisis Resiliensi Keluarga Muslim di Kota Bandung
Authors: Marliani Rosleny
Published: February 2023

Studi ini didasarkan pada fenomena perceraian di kota Bandung yang cukup tinggi. Beberapa alasan yang mengemuka pada umumnya berkaitan dengan kurangnya kebersamaan, kurangnya komunikasi, kekerasan dalam rumah tangga, hingga pemenuhan kebutuhan ekonomi, yang menunjukkan adanya persoalan terkait kedewasaan pasangan dalam membangun resiliensi keluarga. Padahal pernikahan memiliki nilai sakral dalam ajaran agama. Studi ini bertujuan untuk menganalisis bagaimana pengaruh dari kesadaran sakral pernikahan dan kedewasaan pasangan terhadap resiliensi keluarga dengan usia pernikahan sebagai mediator. Studi yang melibatkan 400 keluarga muslim di kota Bandung ini menggunakan pendekatan kuantitatif dan survey online. Sampel ditentukan dengan notasi Slovin dan metode proportional random sampling. Data diolah dengan SPSS menggunakan path analysis. Hasil studi menunjukkan bahwa kesadaran sakral pernikahan (X1) dan usia pernikahan (X2) memiliki peran positif dan signifikan terhadap resiliensi keluarga (Z), dengan kedewasaan diri sebagai mediator (Y). Hasil ini menegaskan pentingnya penyuluh keagamaan untuk mengajarkan tentang nilai sakral dari pernikahan dan kedewasaan terhadap resiliensi keluarga untuk mengurangi angka perceraian pada keluarga muslim di kota Bandung.
Spirituality and Psychological Well-Being of Students Affected by Pandemic Covid-19 in Banda Aceh
Authors: Syahputri Nadia , Safrilsyah Safrilsyah , Fatmawati Fatmawati
Published: February 2023

Spirituality is an attitude that reflects the spirit of religiosity and religion. Spirituality includes many special things such as admiration, gratitude, feelings of love, compassion, and the desire to be close to God. One of the factors that influence spirituality is psychological well-being. This study aims to determine the relationship between spirituality and psychological well-being of UIN Ar-Raniry students. This study uses a quantitative approach with the correlational method. The Sampling was carried out using a proportionate stritified random sampling technique of 342 students at UIN Arraniry, Banda Aceh. Data was collected using two questionnaires, (1)Spirituality Scale which was made based on aspects of Underwood (2006) with a reliability result of α = 0.929, and (2) Psychological Well-Being Scale which was made based on aspects of Ryff (1989) ) with a reliability result of α = 0.927. The data analysis used in this study is the Spearman Rank correlation which shows that there is a relationship between spirituality and psychological well-being, with an r2 value of 0.577, with p = 0.000 (<0.05), which indicates that there is a very significant positive relationship between spirituality with psychological well-being in UIN Ar-Raniry Banda Aceh students affected by Covid-19