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Collaborating Authors
Halliburton
A Novel Turbidity-Based Method to Determine the Insoluble Residue in Polymer Samples
Sabhapondit, Anupom (Halliburton) | Loveless, David (Halliburton) | Harris, Phillip C. (Halliburton) | Nanda, Jajati K. (Halliburton)
Abstract Water-soluble polymers are used to viscosify water-based fracturing fluids. This facilitates the growth of fractures and the placement of proppants. After placing proppants, polymers are removed to maximize productivity. To achieve optimum residual-polymer removal, it is essential to break the polymer gel to a low-viscosity fluid. Internal breakers or an acid flush are commonly used to break the polymer gels. Any insoluble or unbreakable residue can block pore spaces, leading to lower productivity. Therefore, it is very important that the polymers used for fracturing applications contain a minimum amount of insoluble residues or no insoluble residues. In the widely used gravimetric method for determining residue, the polymer is first hydrated and then degraded before using gravimetric techniques. A standard gravimetric method takes more than 24 hr for one polymer sample. The accuracy of the results depends on consistency of laboratory techniques, such as filtration and weighing. Therefore, it was considered worth examining if a turbidity-based method could be developed to determine the insoluble residue quickly. A linear correlation was found between turbidity and acid-insoluble residue of guar. The acid-insoluble residue, after keeping the guar sample in an aqueous fluid at pH 1.0 and 110°F for 24 hr, bears a linear correlation with the turbidity of the solution. The turbidity of guar solution after 2 hr of hydration at pH 7.0 also bears a linear correlation with the acid-insoluble residue. However, the turbidity did not bear any correlation with the total water-insoluble residue. This study led to the development of a turbidity-based method to determine the acid-insoluble residue in guar after approximately 2 hr. This is possibly the first study to correlate turbidity with acid-insoluble residue in guar and has the potential to be used for other polymers as well.
- Asia > Middle East > Saudi Arabia (0.29)
- North America > United States > Texas > Dallas County (0.28)
A New Wireline Rotary Coring Tool: Development Overview and Experience from the Middle East
Rourke, Marvin (Halliburton) | Torne, Juan (Halliburton)
Abstract The prediction of reservoir quality and producibility from petrophysical measurements in carbonates is a well-known challenge. A detailed reservoir characterization requires a suite of petrophysical logs, including imaging, nuclear magnetic resonance, capture spectroscopy for mineralogy, and formation testing logs. These logs are integrated with and often calibrated to measurements made from core analyses. Conventional cores that are cut while drilling are typically time consuming and expensive to acquire; they also require good geological control to pick the required coring depths. Conversely, wireline coring is faster; it provides precise depth control, and core plugs can be selected from a wide range of formations, which would not be practical for conventional coring. In this paper, we introduce a new wireline rotary sidewall coring tool (RSCT™) device that can be used to selectively drill lateral core plugs from the formation. These core plugs are of sufficient size and quality for conventional and SCAL analyses. Recent improvements in the technology enable better core plug quality by providing digital interactive control of the downhole drilling process, which makes the new tool more reliable and less dependent on the experience of the operator. This paper reviews experience and examples in which wireline acquired cores were drilled in various carbonate and silica-clastic reservoirs of the Middle East. The cases include carbonates with oomoldic porosity and brittle-fissile shales.
- Asia > Middle East > Saudi Arabia (0.28)
- North America > United States > Texas (0.28)
- Geology > Geological Subdiscipline (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.56)
New Image Process Technique Reveals New Hidden Formation Structures Using Anisotropy And Dip Images
Perkins, Tegwyn J. (Halliburton) | Proett, Mark (Halliburton) | Stamm, Ron (Halliburton)
ABSTRACT: A new image processing technique has been developed in which resistivity-based image data is used to create new images based on anisotropy. The advantage of imaging tools is that they can provide high resolution geological information in 3 dimensions (i.e., vertically and azimuthally around the borehole). Therefore, it is possible to interpret this data in more detail than with logs that produce only depth-associated information. Consider a resistivity imager that takes an array of measurements around the borehole. This information is composed of an array of measurements much like the pixels in a photograph. These pixels can be displayed so that the position of the points is aligned with depth in the vertical axis and angular displacement in the horizontal axis in a frame of data. Based on the spatial orientation of the data, it is possible to upscale these points to determine the up-scaled horizontal (Rh) and vertical resistivity (Rv) associated with these points. The entire frame of data is resolved into a single-valued point with anisotropy. By repositioning the center point of the frame, a new anisotropy is then determined and an image log is created by processing the entire image. In another step, the axis of the data frame is rotated until a minimum anisotropy is determined, resulting in anisotropy and a dip value associated with that point. As a result, both an anisotropy and dip image can be created by processing the entire image in this manner. These new anisotropy and dip angle images open up an entirely new way of analyzing image data and reveal hidden structures that are not readily apparent in the original image. This new image processing method is used to analyze resistivity image logs, and the results show dramatic new images that enhance the understanding of the geologic structures.
- Europe > United Kingdom (0.46)
- North America > United States (0.28)
ABSTRACT: The Upper Jurassic / Lower Cretaceous Cotton Valley tight gas sand formation has made a significant contribution to North American gas production over the past decades. It is the first significant siliciclastic sediment deposited in the East Texas Basin, and dozens of tight gas fields exist in the Sabine Uplift of East Texas and Louisiana. Stratigraphically compartmentalized fluvial deposits, which are prone to high water cut, dominate the Upper Cotton Valley sandstone. However, laterally continuous, marginal marine lithofacies, confined by two major shales that provide good hydraulic fracture containment, dominate the Lower Cotton Valley sandstones. We acquired a comprehensive dataset of core and log data in a key study well. We conducted detailed routine and special core analyses, including high-pressure mercury injection capillary pressure and benchtop NMR measurements. We have developed a log-based, core-calibrated rock tying method for the Cotton Valley tight gas sand. The study suggests that the rocks have low porosity and low permeability overall, but are not tight enough to hold most of the formation water in the reservoir. Primary depositional facies, clay content, and subsequent diagenesis created complex pore geometry, which is the dominating factor in formation fluid flow. This paper explores the details of data integration of various measurements and demonstrates their reasonable consistency, and explains the petrophysical rock type model. Specifically, it demonstrates the complexities of pore body and pore throat network features of different rock types revealed by NMR data and mercury injection data. By using the rock-type based formation evaluation method, we have established a new definition of "producible pay" zones in this tight gas sand reservoir. INTRODUCTION The Cotton Valley Sandstone in East Texas (Figure 1) consists of tightly cemented, very fine- to fine-grained sandstone interbedded with mudstone, siltstone, and carbonate.
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Tight gas (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (1.00)
- Information Technology > Data Science (0.34)
- Information Technology > Artificial Intelligence (0.34)
- Information Technology > Communications (0.34)
Field Testing of a New LWD Triaxial Sensor For Anisotropy And Dip Measurement In Vertical And Deviated Wells
Bittar, Michael (Halliburton) | Beste, Randy (Halliburton) | Li, Shanjun (Halliburton) | Wu, Hsu-Hsiang (Halliburton) | Althoff, Gary (Sperry Drilling Reservoir Solutions)
ABSTRACT: In the development of a reservoir, it is critical to know the hydrocarbon saturation, which generally requires reliable horizontal and vertical formation resistivities. In recent years, wireline triaxial induction measurements have demonstrated field success in providing resistivity anisotropy in vertical wells with low relative dipping angle. LWD azimuthal measurements have also shown similar field success in providing resistivity anisotropy in formations with high relative dip angle. The success of the wireline triaxial induction relied on antenna configurations that allowed the measurement of the direct and cross coupled components of the coupling matrix. This configuration has posed implementation challenges in harsh LWD environments. This paper discusses the field testing of a new LWD electromagnetic resistivity sensor that employs an antenna configuration having tilted transmitter and tilted receiver antenna orientations that rotate relative to the borehole. The measurements made by this antenna configuration enable the determination of the direct- and cross-coupled components of the coupling matrix and enable the determination of the dip angle, the strike angle, and the vertical and horizontal resistivity of the formation at any relative dip angle while drilling. The principle of operation and the design parameters of the sensor as well as environmental parameters that influence log response are discussed. Field test results along with data processing and inversion schemes are shown. Further topics include the calculation of anisotropy and dip angle while drilling, and the application of such parameters while drilling is highlighted. INTRODUCTION One of the well-known technologies in oilfield exploration is the practice of making detailed records of formations penetrated by a wellbore. Generally, logging tools are used in a borehole to measure surrounding earth parameters by providing a log recorded as a function of a tool's depth or position in the borehole and presenting geology information of underground structures.
- North America > United States > Texas (0.46)
- North America > Canada > Saskatchewan (0.44)
ABSTRACT: Over the years, several equations have been used to compute the photoelectric log of a formation (Pe). Some of these equations lack a density term, resulting in errors; this is obvious when the tool is placed in a tank of water. In addition, the lack of quality test standards or marker beds makes Pe accuracy difficult to verify in all but a few conditions. This leads to the question: what is the proper response equation for computing Pe? To answer that question for a wireline density tool, a Monte Carlo computer-modeling study was undertaken. Two features of computer modeling make it ideal for studying this problem. First, any formation can be easily simulated, so a wide variety of data points can be used to determine the response. Second, non-physical formations can be modeled, which enables the density and Pe responses of the tool to be studied independently. Because the physics behind the Pe measurement is essentially the same for all density tools, the form of the final equation should be applicable to many tools. This study used the ratio of high-energy to low-energy count rates as the primary variable for the calculation. For a given density, it is possible to obtain an accurate Pe response from 0.4 to 15 using a simple function of the ratio. As expected, the generalized equation that is appropriate for all rock densities requires a density term. Accuracy of the technique breaks down for Pe > 15. A review of the physics and concepts behind the Pe measurement explains why the measurement breaks down when Pe > 15, and clarifies why the Pe measurement should be treated as a unitless quantity. INTRODUCTION In 1981, a spectral-density tool was introduced to the industry (Bertozzi et al. 1981).
- Geology > Mineral (1.00)
- Geology > Rock Type > Sedimentary Rock (0.71)
ABSTRACT: Formation permeability is one of the most important parameters controlling reservoir performance. Its importance is reflected by the number of available techniques (well-log evaluation, core measurements, and well testing) typically used to estimate it. Despite significant advances, permeability prediction still remains problematic. This paper presents a robust and inexpensive method of predicting the permeability from the log and/or geological data including the porosity, mineralogy, cement/clay minerals, and grain-size distribution. The approach first reconstructs a representative rock model for the formation at each given depth of interest, which accounts for diagenetic processes such as compaction and cementation due to precipitation of carbonate and clay minerals. The rock models, which are constrained by formation parameters derived from logging data, are used to determine the permeability. The proposed methodology is first tested on 34 sandstone core samples from various geologic settings around the world. Using the mineralogy from the XRD analysis and the grain-size distributions from the thinsection analysis and/or geologic settings, we generate numerical rocks and calculate their permeability. Simulation results are in good agreement with the laboratory measurements, and mostly fall within the ± 2.5 times core permeability. We have also applied the rock modeling technique to field data and predicted the formation permeability at each depth of interest. In this case, all simulation parameters are directly determined from downhole logging measurements including the grain-size distribution and mineralogy. Generally, our predicted permeability falls within the same order of magnitude as the measurements on core samples from the same depth, while the NMR-based Coates model overestimates the permeability in some intervals by more than one order of magnitude. In addition to enhancing the prediction of petrophysical parameters, our approach can be used by geoscientists to explain log responses and their sensitivity to various controlling factors.
- Asia (1.00)
- North America > United States > Texas (0.69)
- Geology > Geological Subdiscipline (1.00)
- Geology > Mineral > Silicate > Phyllosilicate (0.90)
- Geology > Sedimentary Geology > Depositional Environment > Continental Environment > Fluvial Environment (0.47)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.36)
ABSTRACT: Our objective is to unlock the wealth of information contained in drill cuttings in real-time for complementing petrophysical characterization while drilling. The approach is to integrate the direct measurement from drill cuttings with Logging While Drilling (LWD) data to support drilling, geosteering and formation evaluation. In this framework, an accurate mineralogical and lithological characterization of drill cuttings is a key issue. Visual determination for mineralogy via microscopy often substantially varies between analysts, e.g., various mud-logging personnel at the well site and geologists in the office. Further, modern polycrystalline diamond compact (PDC) bits may produce "paste" or "powder," unsuitable for visual/microscopic determination of mineralogy and lithology rather, than regular drill cuttings. A way to tackle the above challenge is performing a geochemical element analysis, by means of Energy-Dispersive X-Ray Fluorescence (ED-XRF). A reliable, portable ED-XRF instrument, robust enough for rig site employment is routinely used for a well site chemostratigraphy service. The instrument produces accurate elemental data, which can, next to its chemostratigraphic applications, be used for mineral and lithology modeling. A methodology has been developed to convert the elemental analysis into a mineralogical composition of the rock sample that is comparable to measurements from full scale X-Ray Diffraction (XRD) laboratory equipment. An experimental setup was deployed assessing the ability to model the mineralogy from geochemical analyses (well site ED-XRF) of a set of rock samples in a "blind" test (Marsala et al., 2011). The analytical results were compared to results obtained from the same samples through state-of-the-art laboratory EDXRF and wave-length dispersive XRF (WD-XRF) instruments. The geochemical data from the well site and the two lab-based instruments show good agreement. Finally, the modeled mineral compositions from wholerock geochemical data were compared with the mineralogy determined from XRD analyses and showed good agreement.
- Europe (1.00)
- Africa (0.69)
- North America > United States (0.69)
- Asia > Middle East > Saudi Arabia (0.49)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (1.00)
- Geology > Geological Subdiscipline > Mineralogy (1.00)
- Geology > Geological Subdiscipline > Geochemistry (1.00)
- (2 more...)
- Well Drilling (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Geologic modeling (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)
- Reservoir Description and Dynamics > Formation Evaluation & Management (1.00)
Advancements In Carbon-Oxygen Surveillance Of The Deepwater Gulf Of Mexico Mars Waterflood
Cuttitta, Matt (Shell Exploration & Production Company) | Weiland, Jeff (Shell Exploration & Production Company) | Suparman, _ (Halliburton) | Fox, Phil (Halliburton) | Setiadi, Ismar (Halliburton)
ABSTRACT: The primary purpose of the Mars (Mississippi Canyon 807) waterflood in the deepwater of the Gulf of Mexico (GOM) is to increase recovery efficiency in three main reservoirs. A robust surveillance logging program has been conducted in the field since 1996. Measurements have included strain, flow profile, reservoir layer pressure, casing inspection, and multi-component fluid saturation evaluations. The fluid saturation surveillance results derived from log measurements have historically been based on original porosity estimates. More recent analysis techniques have included reductions in porosity due to compaction to better understand fluid distributions and eliminate anomalous saturation indications. The newly developed modeling can observe and more accurately identify injected seawater at the observation wells. This fluid identification is accomplished through recently developed interpretation methods using pulsed neutron sensors including inelastic carbon-oxygen (C/O mode) and capture sigma (mode). The method is demonstrated with several Mars examples including discussion of interpretations. Surveillance of the Mars field is critical to optimizing recovery. The cased hole logging data are integrated with other subsurface data, including 4D seismic, additional openhole logs from new wells, production data, and injection data. This dataset allows the team to properly operate existing wells, identify additional opportunities, and plan future activities. Carbon-oxygen and sigma surveillance has provided an understanding of the fluid changes within the reservoirs under the influence of compaction, water injection and aquifer movement. Through experiences in several reservoirs, anomalous tri-fluid (oil, native formation water and injected waterflood seawater) saturation estimates were identified. The proper evaluation of multiple fluids is dependent on the porosity of the rock matrix system. After application of measured strain and porosity reduction modeling, estimates obtained were more representative than what conventional analysis would derive. Techniques are demonstrated that help identify fluid and porosity changes in the volume observed by the pulsed neutron tool.
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.47)
- Geology > Geological Subdiscipline (0.46)
- North America > United States > Gulf of Mexico > Central GOM > East Gulf Coast Tertiary Basin > Mississippi Canyon > Block 851 > Mars Field (0.99)
- North America > United States > Gulf of Mexico > Central GOM > East Gulf Coast Tertiary Basin > Mississippi Canyon > Block 850 > Mars Field (0.99)
- North America > United States > Gulf of Mexico > Central GOM > East Gulf Coast Tertiary Basin > Mississippi Canyon > Block 808 > Mars Field (0.99)
- (7 more...)
The Link Between Resistivity Contrast And Successful Geosteering
Seifert, Douglas (Saudi Aramco) | Chemali, Roland (Halliburton) | Bittar, Michael (Halliburton)
ABSTRACT: Proactive geosteering anticipates reservoir exits before they occur, thus enabling well paths to be altered to navigate within the desired portion of the reservoir. This paper quantifies the importance of the resistivity levels within the hydrocarbon zone and within the adjacent intervals for successful proactive geosteering. Resistivity contrast, expressed as the difference between the conductivities of the reservoir and of the adjacent interval, emerges as the key parameter. Large contrast and sharp transitions in resistivity levels are shown to be favorable for proactive geosteering, whereas gradational transitions are often challenging. These observations are substantiated and quantified with models and actual case histories. The key enabling geosteering technology considered is the newly deployed azimuthal deep resistivity family of logging-while-drilling (LWD) sensors. These sensors yield multiple real-time measurements and images to help visualize the geological strata in the vicinity of the wellbore. The deepest reaching and most relevant type of measurement is the geosignal, which reflects lateral changes in resistivity away from the well. Geosignals can detect and locate an approaching boundary from several feet. Numerical and experimental modeling have been performed for a wide variety of resistivity contrasts and transition types. Graphical representations of the results suggest a near-exponential dependency on the distance separating the well path from the boundary and a strong relationship to the resistivity contrast. It is shown in particular that low resistivity shale can be seen from nearly 20 ft away when the sensor is in the reservoir. The range of detection is reduced to only 6 ft when drilling in the shale and attempting to detect the reservoir. Case studies from actual geosteered wells support the performance predicted by the theoretical models. Guidelines are derived for planning and interpreting a proactive geosteering operation.
- Europe (0.93)
- Asia > Middle East > Saudi Arabia (0.47)
- North America > United States > Colorado (0.28)
- Research Report > New Finding (0.66)
- Research Report > Experimental Study (0.48)
- Europe > Norway > North Sea > Northern North Sea > North Viking Graben > PL 104 > Block 30/9 > Oseberg Field > Tarbert Formation (0.99)
- Europe > Norway > North Sea > Northern North Sea > North Viking Graben > PL 104 > Block 30/9 > Oseberg Field > Oseberg Formation (0.99)
- Europe > Norway > North Sea > Northern North Sea > North Viking Graben > PL 079 > Block 30/9 > Oseberg Field > Tarbert Formation (0.99)
- (3 more...)