To maximize oil and gas production profitability, it is paramount to reach the whole reservoir and extract the hydrocarbon resources efficiently. In offshore environments well prospects are sited at fracture gradients and narrow pressure gradients. Thus in this type of environment drilling hazards are aplenty and this makes wellbore completion a tough challenge. If the wellbore is not completed properly then there can be an economic as well as environmental disaster. In such situations there often exists a drilling window between fracture pressure gradient and also pore pressure through which when drilling done yields out proper results. Thus this paper overviews the possibility of applying MPD technique in Well construction and completion in offshore conditions. The experimental as well as onsite usage of MPD technique has proved so far that this technique performs quicker and better than the conventional drilling technique which drills without any wellbore pressure management. Also the environmental hazards and risks related to conventional drilling usage in offshore hostile conditions are lowered through MPD. MPD can also reduce NPT as well as reduce drilling fluid loss which can in return lower the OPEX. MPD can also add value to production casings cementing operations in HPHT wells and also mitigate any further damage to wellbore.Here in this paper MPD techniques and its case studies of usage on various offshore fields of India are reviewed and then the unique challenges associated with application of MPD in offshore basins of India are highlighted. Also here a proper drilling program using MPD has been proposed for various petroliferous basins of India. Albeit few offshore basins of India which have established proven reserves, many are still loosely explored and thus with the information available a new proposal using MPD has been conceived here for basins which are petroliferous for further drilling activity in the proposed basin. This in return will add knowledge to the stakeholders, government and operators for future planning and development of field. An effective comparison between conventional and MPD technique has also been highlighted in this paper for regulators of hydrocarbon industry for basic understanding of MPD.

Enormous percentage of total original oil in place lies in the fractured reservoirs. There dual permeability plays an important role to enhance the oil production rate which is governed by the large surface area provided by fractures so that fluids can move easily from low permeability zone matrix to high permeability channeled network zone. Convective current is setup in reservoir due to density inversion. This creates a favorable condition of mass transfer by diffusion. Due to high geo thermal gradient and convective motion of fluids in geothermal reservoir, diffusion can lead to the elevation or depression of bubble point pressure. When reservoir pressure gets drops it leads to evolution of gas from matrix zone which eventually gets transferred to gas cap. This leads to depression of Bubble Point. Now, when reservoir pressure increases it leads to transportation of gas from gas cap to matrix zone. This leads to elevation of Bubble point. In this paper a quantitative analysis of diffusion process for an arbitrary inclined fracture [1] by the help of FICK'S law of diffusion and continuity equation of diffusion is done. Through this analysis we obtain a final differential equation by applying material balance on the dissolved gas in the fracture. Lastly effective diffusion coefficient of the fractured media is quantitatively analyzed.Thus, correct analysis of reservoir in terms of microscopic and macroscopic sweep efficiency is done by the inclusion of this diffusion process. Hence, a better model to simulate the fractured reservoir can be made by selecting appropriate boundary conditions for the final differential equation obtained and proposed in this paper. Also we can understand the actual solution gas drive mechanism in the fractured reservoirs correctly. Negligible works have been done on the Mass Transfer analysis in the inclined fractured reservoir theoretically or experimentally and thus here an effective mathematical model of the mass transfer in an arbitrary inclined fracture has been formulated and presented for regulators of hydrocarbon industry for high outcome from a field.

This paper relates to the method of exploration for hydrocarbons and minerals in particular by using artificial and natural thermoluminescence and cathodoluminescence analysis methods. Luminescence is the emission of light from a solid which is excited by some form of energy. Thermoluminescence is the phenomenon of emission of light caused by thermal activation of trapped excess electrons and their corresponding electron deficient sites. Generally quartz, carbonates (calcite and dolomite) and the feldspar groups determine thermoluminescent properties. Here the possibilities of application of artificial Thermoluminescence to determine the proximity of a core sample to a Hydrocarbon reserve are reviewed. The advantages of using thermoluminescence after geophysical exploration is to pinpoint the exact location of Hydrocarbon and Minerals reserve. In Cathodoluminescence the excitation of electrons is achieved by electron beam. Here we see how Cathodoluminescence can be used to know the petro physical properties of the sample, which will in future aid to the knowledge of accurate characterization of reservoir. Nowadays Geophysical way of exploration is used worldwide. In this process mainly we do seismic surveys and based on their travel time an approximate image of the subsurface is generated. Thermoluminescence and Cathodoluminescence can complement the exploration by geophysical prospecting and can add certainty to locate the zone of interest. Thus more accuracy and precision are achieved by bridging geophysical analysis with logging data. Sensitivity of Thermoluminescence and Cathodoluminescence have also been covered here. Mineral and Hydrocarbon exploration both can be done side by side. Hence it can help link Oil and Gas Company with mineral exploration company and reduce cost of exploration. Thus here we aim to assemble past ideas and invention, current works on the topic in the fields and future scope of the methods proposed here for exploration.

This paper presents a comprehensive field study of an openhole completion with standalone screens using a unique filtercake breaker treatment, compatibility with reservoir fluids, cost effectiveness, and overall performance-based comparative results to meet the challenges of drilling and completing offshore wells.In the offshore field of Krishna-Godavari Basin, Bay of Bengal, one of the most prolific hydrocarbon basins of India, synthetic-based reservoir drill-in fluids (SB-RDFs) were used to drill the reservoir section, which was then completed openhole using standalone sand-control screens. In order to control fluid invasion to the formation, a major cause of formation damage, the designed RDF created a filtercake at the sandface. However, high flow initiation pressure caused high skin effect and compromised completion efficiency. The primary challenge during completion was to clean up the SB-RDF filtercake from the reservoir section to remove near-wellbore damage and maximize productivity. Another challenge was to avoid the high potential of filtercake plugging of the screens, which could lead to higher drawdown pressures and possible early screen failure. To address these challenges, a filtercake breaker for the SB-RDF was developed to lower the skin factor thus maximizing production and mitigating the risks of plugging the sand-control screens. After implementing this customized breaker solution, combined with a precise placement program, the wells showed a tremendous reduction in the skin factor and a significant increase in completion efficiency, compared to wells with the same reservoir properties completed in earlier campaigns.An organic acid pre-cursor enabled filtercake breaker placement and soaking without being chemically spent during circulation. Additional breaker design criteria included the ability to break the RDF emulsion, water-wet the solids in the filtercake, dissolve the calcium carbonate used as bridging material in the SB-RDF, and disperse the non-acid soluble material without plugging the screens.The paper presents a detailed study of the main challenges while formulating and evaluating the filtercake breaker solution. Additionally, a production results comparison is made between the well using the customized filtercake breaker treatment and previous well completion and breaker treatments. The paper also discusses the comprehensive displacement program and required spacers for precise placement of the breaker in the openhole and offshore pit management.

This paper presents a comprehensive laboratory and field study discussing development, formulation, and application of a new flat rheology drilling fluid system that meets the challenges faced when drilling in an ultradeepwater well environment. The use of this new flat rheology drilling fluid system for the first time in Asia-Pacific Region has created the potential to efficiently drill more challenging deepwater and ultra deepwater wells in offshore Myanmar, Malaysia, and other associated countries. In a deepwater block situated on Myanmar's west coast, conventional synthetic-based drilling fluids (SBM) have been used to drill all the wells to date. During the planning phase of an ultradeepwater well with a water depth of 2,300 m, it was found that the equivalent circulating density (ECD) with a narrow pore pressure and fracture gradient would have increased downhole complications leading to non-productive time (NPT). The main concern was not being able to reach total depth (TD) or successfully setting casing on bottom with the original well design, requiring implementation of a contingency casing and pushing the operational cost over authority of expenditure (AFE). To overcome the challenges, a new flat rheology drilling fluid system was introduced based on ECD challenges and rheology requirements. The initial study of modelled hydraulics showed a significant ECD reduction using a flat rheology drilling fluid system. The first round of laboratory tests exhibited promising results of flat rheology across all temperature ranges and after iterating numerous formulations developed with local seed mud were narrowed down to two final formulations of 1.08 sg and 1.17 sg. The formulation was field trialed with some slight adjustment in chemical concentrations to meet specific field mud properties. The well was drilled successfully with no major variation in ECD or issues related to the large temperature range. Implementing this customized solution combined with precise strategy led to successful results in efficiently completing one of the most challenging wells of the campaign. The paper presents a comprehensive study of the challenges formulating and implementing a new flat rheology drilling fluid system. Additionally, a detailed study on ECD challenges when drilling an ultradeepwater well is also done. The paper also discusses the comprehensive pit management program and required treatment plan for drilling. Finally, the paper aims to compare the existing results with previous drilling techniques, which will assist operators with the future advances in similar fields.