Heera field is one of the most prolific fields in the Mumbai offshore basin in India. The field belongs to one of the six tectonic blocks (Heera-Panna-Basseinn block) of Mumbai offshore basin. Carbonates are by far the major contributor in terms of hydrocarbon production in this field. Presence of Vugs, Fractures and Solution enhanced features makes it a real challenging job to understand the porosity distribution within this reservoir. Characterizing and quantifying the complex secondary porosity profile and identifying different flow unit is immensely important for production optimization and appropriate completion design. The challenge of understanding the porosity heterogeneity of Carbonate reservoir further increases where critical borehole condition averts the possibility of running high resolution Wireline imaging tool. A novel approach has been taken for the first time in this field to quantify and characterize the secondary porosity distribution and permeability prediction from high resolution LWD Resistivity Image. Good quality LWD Resistivity Image has been processed using advance processing software and a quantified result of secondary porosity spectrum was obtained using robust algorithm. This quantified secondary porosity result is further utilized to characterize the different high resolution flow unit throughout the borehole. This paper illustrates a case study where quantified result of secondary porosity and estimated permeability has been derived using LWD resistivity image in conjunction with the openhole measurements.Micro-facies variation in terms of fluid flow characterization, size & nature of vugs and laminated beds has been established. This will lead to accurate completion designing for production optimization. The result was then validated with the secondary porosity derived from the high resolution Wireline Image and Mobility data from samplingtool.In a nutshell, this work opens a new regime of application of LWD image in terms of advance Geological and Petrophysical interpretation in addition to its other benefits like borehole stability and Geosteering capability.

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The current study was carried out in one of the most economically viable gas-bearing reservoirs in Japan, the Minami-Nagaoka volcanic field, located to the southwest of Nagaoka. Petroleum deposits occur in deep-seated underwater volcanic rocks of Miocene age, and these deposits contribute significant amount of Japan's total natural gas production. Because of the steep rise in domestic gas demand, re-examination of the existing data sets was performed to understand the geological reason for the extreme lateral facies variation, the complex facies distribution pattern, and production uncertainties. The study revealed a very interesting geological phenomenon of multiple eruption vents that is responsible for the complex facies association and distribution pattern within the study area. A robust workflow was designed through maximizing utilization of existing high-resolution datasets to solve the current challenges in the field. At the beginning of the workflow, different complex underwater volcanic facies were recognized in image, core, and log data. After volcanic facies reconstruction in each well, facies associations and their distribution pattern across wells were visualized. Finally, using background geological knowledge and well-based facies identification and correlation, a model with multiple volcanic eruption vents was conceptualized within the study area from north to south. In addition, the probable location of different drilled wells relative to the location of the multiple volcanic vents was defined based on the facies assemblages of each well. The present work demonstrates a unique way to conceptualize and model the paleovolcanic eruption events within a volcanic field. Understanding the paleovolcanic eruption model is key for proper understanding of the facies distribution pattern and facies variation across wells and for finding the best drilling location for hydrocarbon exploration wells. It was observed that the facies with a high amount of lava are located close to the volcanic vent, and wells with a higher amount of brecciated facies are located farther from the volcanic vent. Another type of facies, which is unique for underwater volcanism, is the hyaloclastite (glassy type) facies; this facies is located towards the margin of the volcanic vents. In addition, lateral facies variation was clearly understood after visualizing the eruption model, which was no possible prior to the present study. The current workflow demonstrates a novel approach for better understanding the paleogeological condition for a unique type of gas-bearing submarine volcanic reservoir, which is a very rare example in the present oil and gas industry. The technique in this work represents a new way of looking high-resolution well data for geological modeling and evaluation of any volcanic field.

Prime objective of horizontal wells is to enhance production by maximizing reservoir contact. Hence it is extremely essential for deviated section to land accurately on top of pay horizon followed by optimum placement of horizontal section. Lateral formation heterogeneity in terms of thickness, lithology and stratigraphic pinching out makes proper horizontal well drilling through deltaic silty-sand reservoir in Wasna field, India; a real challenging job. Absence of Seismic data also adds structural dip uncertainty to the complexity of these targets. Real-time decisions making via optimal well placement technology are useful to drill these wells in a cost effective manner.In the studied field, several attempts were taken previously to drill horizontal well geometrically but the production result was never encouraging. Manifold production enhancement through accurate horizontal drilling has been achieved using conventional well placement method for the first time in this field. Well Placement workflow involves real time well trajectory designing while drilling based on layer earth model updation using LWD Image and Log data.The high resolution LWD images in real time have been instantaneously utilized to compute the orientation of the geological features across the borehole with high degree of accuracy. These computed orientations along with real time log data is used to update the near wellbore structural and stratigraphic model. Accurate configuration of subsurface layer earth architecture helped in effective forward designing of the well trajectory.This interactive 24X7 real time process finally enabled the successful horizontal well drilling within 1.5 m thick sweetest part of the reservoir. The well was placed with 95% NTG resulting around 5 times increment in initial production compared to the other existing horizontal well. This paper illustrates an extraordinary successful case study which opens new and exciting possibilities for horizontal well drilling campaign in the Western Onshore India. IntroductionIn many of the fields nowadays, horizontal drainholes, over vertical wells, are perceived as a better means of exploitation of the reservoir. But, boundary navigation and optimizing the drainhole within the desired target layer posses the biggest challenge in this regard.