Most oil and gas leases allow the operator to extend possession for an indefinite period by establishing production in paying quantities. We show how this option to “hold by production” (HBP) stimulates the drilling of many wells that would otherwise be uneconomic. Although such wells may superficially appear to be poor investments, in fact they contribute to shareholder value. We also show, ho...

BACKGROUND Hydraulic fracturing technologies, developed over the last 65 years, have only recently been combined with horizontal drilling to unlock oil and gas reserves previously deemed inaccessible. Although these technologies have dramatically increased domestic oil and natural gas production, they have also raised concerns for the potential contamination of local water supplies with the app...

Compositional distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in Nigerian oil-based drill-cuttings have been studied for evidence of petrogenic and/or pyrogenic effects with recommendations for the strict enforcement of the ban on the use of oil-based mud in drilling by government regulatory agencies and prior bio-treatment of the drill cuttings before final fate. Laboratory...

various adjuvants carry out different functions depending on the herbicides types and the target species. outdoor pot experiments were conducted to evaluate the effects of three post-emergence herbicides, namely, clodinafop-propargyl, haloxyfop-p-methyl, and difenzoquat-methyl-sulfate, as influenced by two adjuvants, on wild oat (avena ludoviciana durieu.) control. the study was carried out at ...

To ensure safe and stable drilling operation, bottom hole pressure (BHP) should be kept within some region. However measurement of the BHP is sometimes not available or reliable, especially when the circulation is low, e.g., during pipe connection procedures. This paper presents the application of a moving horizon estimation (MHE) method for online estimation of the BHP during petroleum drillin...

Logging while drilling (LWD) is a drilling technique which obtains and transmits the logging data during oil/gas drilling operations. Because of the limited available transmission bandwidth of mud channel, how to improve the bandwidth utilization becomes a critical problem in LWD research. In this paper, by discussing the information entropy of real logging data, we find that the original encod...

Public health concerns related to the expansion of unconventional oil and gas drilling have sparked intense debate. In 2012, we published case reports of animals and humans affected by nearby drilling operations. Because of the potential for long-term effects of even low doses of environmental toxicants and the cumulative impact of exposures of multiple chemicals by multiple routes of exposure,...

The increasing global energy demand has pushed the oil industry towards developing more innovative and advanced methods of enhancing oil recovery even under unfavourable technical and environmental conditions. The severity of many operational problems affecting the drilling and production of oil and gas wells is worsened by inaccessibility; hence, remedial efforts must be implemented from afar....