Significance This work reports direct measurements of methane emissions at 190 onshore natural gas sites in the United States. The indicate that well completion are lower than previously estimated; data also show from pneumatic controllers and equipment leaks higher Environmental Protection Agency (EPA) national emission projections. Estimates total similar to most recent EPA inventory production. These will help inform policymakers, researchers, industry, providing information about some...

Abstract Our main result is the discovery of an optimum acid injection rate to obtain breakthrough in linear corefloods carbonates using a minimum total volume. Low rates spending at core surface while high formation multiple, highly ramified wormholes. At intermediate rate, single, small wormhole penetrates core. The found be function rock composition and reaction temperature as well pore size distribution virgin rock. All these factors are included theory developed here. This provides...

Emissions from 377 gas actuated (pneumatic) controllers were measured at natural production sites and a small number of oil sites, throughout the United States. A subset devices (19%), with whole emission rates in excess 6 standard cubic feet per hour (scf/h), accounted for 95% emissions. More than half recorded emissions 0.001 scf/h or less during 15 min measurement. Pneumatic level control applications on separators compressor had higher other types applications. Regional differences...

Abstract Horizontal wells intersecting multistage transverse fractures created by low viscosity fracturing fluid with proppant loadings are the key to revitalizing production from Mississippian Barnett shale of Fort Worth Basin in Texas. However, direct laboratory measurements both natural and induced fracture conductivities under realistic experimental design conditions needed for reliable well performance analysis optimization. In this work, a series experiments were conducted measure...

Methane emissions from liquid unloadings were measured at 107 wells in natural gas production regions throughout the United States. Liquid clear of accumulated liquids to increase production, employing a variety lifting mechanisms. In this work, with and without plunger lifts sampled. Most unload less than 10 times per year averaging 21 000–35 000 scf methane (0.4–0.7 Mg) event (95% confidence limits 000–50 scf/event). For lifts, averaged 1000–10 (0.02–0.2 500–12 Some are automatically...

Summary Matrix-acidizing models have traditionally underpredicted acid-stimulation benefits because of underprediction wormhole penetration and the corresponding magnitude completion-skin factors in vertical wells. For long horizontal wells drilled carbonate reservoirs, productivity enhancement is a function acid placement effective penetration. However, prediction requires more analysis than that provided by current industry models. This paper presents results matrix-acid modeling work for...

Summary Horizontal wells that intersect multistage transverse fractures created by low-viscosity fracturing fluid with low proppant loadings are the key to revitalizing production from Mississippian Barnett shale in Fort Worth basin Texas. However, direct laboratory measurements of both natural- and induced-fracture conductivities under realistic experimental-design conditions needed for reliable well-performance analysis fracture-design optimization. In this work, a series experiments was...

Summary In this paper, we present a new analytical model for formation damage skin factor and the resulting reservoir inflow, including effect of anisotropy heterogeneity. The shape damaged region perpendicular to well is based on pressure equation an anisotropic medium and, thus, circular near elliptical far from well. can be used various distributions along well, depending time exposure during drilling completion. inflow damaged, parallel-piped-shape illustrates importance ratio thickness...

Abstract Various fracture interaction criteria were reviewed and a systematic study is presented to analyze the effect of natural fractures on hydraulic propagation. From literature review, approach Warpinski Teufel was adopted evaluat propagation that would occur after intersects an existing fracture. The determined conditions differential stress, angle intersection, toughness for which dilation occur. Criteria subsequent modes are then presented.

Abstract The conductivity of an acid-etched fracture depends strongly on void spaces and channels along the resulting from uneven acid etching walls. In this study, we modeled deformation rough surfaces acidized in heterogeneous formations based synthetic permeability distributions developed a new correlation to calculate conductivity. our previous work, dissolution having small-scale heterogeneities permeability. characterization correlated fields rock includes average permeability,...

Summary The purpose of matrix stimulation in carbonate reservoirs is to bypass damaged areas and increase the effective wellbore area. This can be achieved by creating highly conductive flow channels known as wormholes. A further injection acid will follow a wormhole path where permeability has increased significantly, leaving substantial intervals untreated. problem more significant contrast increases within target zones. Diverting materials, such viscoelastic-surfactant (VES) -based acids,...

Abstract During hydraulic fracturing, temporarily plugging existing fractures and diverting the injected slurry further into newly created is beneficial for maximizing reservoir contact productivity. Typically, flows path of least resistance, which may not always align with targeted stimulation zones. Consequently, this can result in leaving many inadequately propped, as much proppants settle near wellbore or are lost overtreated fractures. To understand fracture-propped area transport fluid...

Abstract Limited entry design has been utilized to enhance distribution of fracture fluid and proppant across clusters in multi-stage stimulation for horizontal wells. The concept uses limited perforation diameter/number generate frictional pressure drop control through perforations, the goal is evenly distribute over all clusters. However, today's field practice, high injection rate large volume often lead severe erosion resulting reduced friction lower fracturing efficiency. Distributed...

Summary The efficiency of the matrix acidizing process in carbonates depends strongly on wormholing phenomenon—if wormholes are formed, effects near-wellbore damage can be overcome with relatively small volumes acid. Numerous previous studies have shown that wormhole patterns placed these general categories: compact dissolution which most acid is spent near rock face; pattern; and uniform many pores enlarged, as typically occurs sandstone acidizing. We developed a theory process, predicts...

Summary With the recent development of temperature measurement systems such as fiber-optic distributed sensors, continuous profiles in a horizontal well can be obtained with high precision. Small changes resolution on order 0.1°F detected by modern temperature-measuring instruments intelligent completions, which may aid diagnosis downhole flow conditions. Since producing fluid inflowing is not affected elevational geothermal changes, primary differences for each phase (oil, water, and gas)...

Abstract Multilayer transient testing is designed for determining individual layer properties (permeability and skin) multiple layers commingled in a well. Traditional multilayer requires combination of rate profiles from production log pressure measurements acquired at surface rates. This method can be time consuming may involve significant errors depending on the accuracy flow measurements. Today, many wells are equipped with downhole sensors that provide distributed or multipoint...

Summary In the acid-fracturing process, fracture conductivity created by acid etching of walls is because surface roughness acid's nonuniform dissolution surfaces. The acid-fracture dependent on patterns, which are determined permeability and mineralogy distributions. That is, spatial distribution affects conductivity, cannot be considered in laboratory measurements use core samples that too small to observe such macroscale heterogeneities, or typical simulators, gridblock size much larger...

Abstract The matrix acidization of sandstone by a hydrochloric/hydrofluoric acid mixture is described through use capillary model. model was solved first in linear coordinates so that it could be compared with the results coreflood experiments performed on Berea sandstone. predictions showed reasonable agreement experimental data and yielded specific information about reaction characteristics sand-stone/HCl/HF system. then applied radial to generate design curves for treatment. While these...

Abstract Artificially created fracture networks with sufficient conductivities are essential for economic production from shale reservoirs. Fracture conductivity can be significantly reduced in formations due to severe proppant embedment. In addition, embedment induces flakes that migrate and clog networks. A laboratory investigation was performed understand how excessive caused by the shale-water interaction impairs conductivity. The experiments were conducted using Barnett samples...